This section defines a set of objects and
	interfaces for accessing and manipulating document objects.
	The functionality specified in this section (the
	Core functionality) is sufficient to allow
	software developers and web script authors to access and
	manipulate parsed HTML and XML content inside conforming
	products. The DOM Core API also allows creation and population
	of a Document object using only DOM API calls; loading
        a Document and saving it persistently is left
        to the product that implements the DOM API.
The DOM presents documents as a hierarchy of Node
	objects that also implement other, more specialized interfaces. Some
	types of nodes may have child nodes of various types, and others are
	leaf nodes that cannot have anything below them in the document
	structure. For XML and HTML, the node types, and which node types they
	may have as children, are as follows:
        
Document --  Element (maximum of
	      one), ProcessingInstruction, Comment,
	      DocumentType (maximum of one) DocumentFragment --  Element,
	      ProcessingInstruction, Comment,
	      Text, CDATASection,
	      EntityReference DocumentType -- no childrenEntityReference -- Element,
	      ProcessingInstruction, Comment,
	      Text, CDATASection,
	      EntityReference Element -- Element,
	      Text,  Comment,
	      ProcessingInstruction, CDATASection,
	      EntityReferenceAttr -- Text,
	      EntityReferenceProcessingInstruction --  no childrenComment --  no childrenText --  no childrenCDATASection --  no childrenEntity -- Element,
	      ProcessingInstruction, Comment,
	      Text, CDATASection,
	      EntityReferenceNotation --  no childrenThe DOM also specifies a NodeList interface to handle
        ordered lists of Nodes, such as the children of a
        Node, or the elements returned by the
        getElementsByTagName method of the Element
        interface, and also a NamedNodeMap interface to handle
        unordered sets of nodes referenced by their name attribute, such as the
        attributes of an Element.  NodeList and NamedNodeMap
        objects in the DOM are live; that is,
        changes to the underlying document structure are reflected in all
        relevant NodeList and NamedNodeMap objects.
        For example, if a DOM user gets a NodeList object
        containing the children of an Element, then subsequently
        adds more children to that element (or removes children, or modifies
        them), those changes are automatically reflected in the
        NodeList, without further action on the user's
        part. Likewise, changes to a Node in the tree are
        reflected in all references to that Node in
        NodeList and NamedNodeMap
        objects.
Finally, the interfaces Text, Comment, and
        CDATASection all inherit from the
        CharacterData interface.
Most of the APIs defined by this specification are 
	interfaces rather than classes.  That means that 
	an implementation need only expose methods with 
	the defined names and specified operation, not
	implement classes that correspond directly to the interfaces.
	This allows the DOM APIs to be implemented as a thin veneer on top
	of legacy applications with their own data structures, or 
	on top of newer applications with different class hierarchies.
	This also means that ordinary constructors (in the Java or C++
	sense) cannot be used to create DOM objects, since the 
	underlying objects to be constructed may have little relationship
	to the DOM interfaces. The conventional solution to this in
	object-oriented design is to define factory methods
	that create instances of objects that implement the various
	interfaces.  In the DOM Level 1, objects implementing some
	interface "X" are created by a "createX()" method on the 
	Document interface; this is because all DOM objects live
	in the context of a specific Document.
The DOM Level 1 API does not define a standard
	way to create DOMImplementation or Document
	objects; DOM implementations must provide
	some proprietary way of bootstrapping these DOM interfaces, and
	then all other objects can be built from there.
The Core DOM APIs are designed to be compatible with a wide range of languages, including both general-user scripting languages and the more challenging languages used mostly by professional programmers. Thus, the DOM APIs need to operate across a variety of memory management philosophies, from language bindings that do not expose memory management to the user at all, through those (notably Java) that provide explicit constructors but provide an automatic garbage collection mechanism to automatically reclaim unused memory, to those (especially C/C++) that generally require the programmer to explicitly allocate object memory, track where it is used, and explicitly free it for re-use. To ensure a consistent API across these platforms, the DOM does not address memory management issues at all, but instead leaves these for the implementation. Neither of the explicit language bindings devised by the DOM Working Group (for ECMAScript and Java) require any memory management methods, but DOM bindings for other languages (especially C or C++) may require such support. These extensions will be the responsibility of those adapting the DOM API to a specific language, not the DOM Working Group.
While it would
	be nice to have attribute and method names that are short,
	informative,  internally consistent, and familiar to users of
	similar APIs,  the names also should not clash with the names
	in legacy APIs  supported by DOM implementations.
	Furthermore,  both OMG IDL and ECMAScript have
	significant limitations in their ability to disambiguate names
	from different namespaces that make it difficult to avoid naming
	conflicts with short, familiar names. So, some DOM names tend to be
	long and quite descriptive in order to be unique across all
	environments.
      
The Working Group has also attempted to be internally consistent in its use of various terms, even though these may not be common distinctions in other APIs. For example, we use the method name "remove" when the method changes the structural model, and the method name "delete" when the method gets rid of something inside the structure model. The thing that is deleted is not returned. The thing that is removed may be returned, when it makes sense to return it.
The DOM Core APIs present two somewhat different sets of
	interfaces to an XML/HTML document; one presenting an "object
	oriented" approach with a hierarchy of inheritance, and a
	"simplified" view that allows all manipulation to be done via
	the Node interface without requiring casts (in
	Java and other C-like languages) or query interface calls in
	COM environments. These operations are fairly expensive in Java and
	COM, and the DOM may be used in performance-critical
	environments, so we allow significant functionality using just the
	Node interface. Because many other users will find the
	inheritance hierarchy easier to understand than the
	"everything is a Node" approach to the DOM, we also
	support the full higher-level interfaces for those who prefer a more
	object-oriented API. 
In practice, this means that there is a certain amount of
	redundancy in the API. The Working Group considers the
	"inheritance" approach the primary view of the API, and the
	full set of  functionality on Node to be "extra"
	functionality that users may employ, but that does not eliminate
	the need for methods on other interfaces that an
	object-oriented analysis would dictate. (Of course, when the
	O-O analysis yields an attribute or method that is 
	identical to one on the Node interface, we don't
	specify a completely redundant one.) Thus, even though there
	is a generic nodeName attribute on the Node
	interface, there is still a tagName attribute on the
	Element interface; these two attributes must
	contain the same value, but the Working Group considers it
	worthwhile to support both, given the different constituencies
	the DOM API must satisfy. 
DOMString typeTo ensure interoperability, the DOM specifies the following:
A DOMString is a sequence of 16-bit units.
typedef sequence<unsigned short> DOMString;
DOMString using UTF-16
        (defined in [Unicode] and Amendment 1 of
	[ISO/IEC 10646]).DOMString (a high surrogate and
        a low surrogate).Note: Even though the DOM defines the name of the string type to
        be DOMString, bindings may use different names. For
        example for Java, DOMString is bound to the
	String type because it also uses UTF-16 as its
	encoding.
Note: As of August 1998, the OMG IDL specification included a
      wstring type. However, that definition did not meet the
      interoperability criteria of the DOM API since it relied on
      negotiation to decide the width and encoding of a character.
The DOM has many interfaces that imply string matching. HTML
      processors generally assume an uppercase (less often, lowercase)
      normalization of names for such things as elements, while XML is
      explicitly case sensitive. For the purposes of the DOM, string
      matching is performed purely by binary comparison of the
      16-bit units of the
      DOMString. In addition, the DOM assumes that any
      case normalizations take place in the processor, before
      the DOM structures are built.
Note: Besides case folding, there are additional normalizations that can be applied to text. The W3C I18N Working Group is in the process of defining exactly which normalizations are necessary, and where they should be applied. The W3C I18N Working Group expects to require early normalization, which means that data read into the DOM is assumed to already be normalized. The DOM and applications built on top of it in this case only have to assure that text remains normalized when being changed. For further details, please see [Charmod].
The interfaces within this section are considered fundamental, and must be fully implemented by all conforming implementations of the DOM, including all HTML DOM implementations, unless otherwise specified.
DOM operations only raise exceptions in "exceptional"
      circumstances, i.e., when an operation is impossible
      to perform (either for logical reasons, because data is lost, or 
      because the implementation has become unstable). In general, DOM methods
      return specific error values in ordinary
      processing situations, such as out-of-bound errors when using
      NodeList. 
    
Implementations may raise other exceptions under other circumstances.
    For example, implementations may raise an implementation-dependent 
    exception if a null argument is passed. 
Some languages and object systems do not support the concept of exceptions. For such systems, error conditions may be indicated using native error reporting mechanisms. For some bindings, for example, methods may return error codes similar to those listed in the corresponding method descriptions.
exception DOMException {
  unsigned short   code;
};
// ExceptionCode
const unsigned short      INDEX_SIZE_ERR                 = 1;
const unsigned short      DOMSTRING_SIZE_ERR             = 2;
const unsigned short      HIERARCHY_REQUEST_ERR          = 3;
const unsigned short      WRONG_DOCUMENT_ERR             = 4;
const unsigned short      INVALID_CHARACTER_ERR          = 5;
const unsigned short      NO_DATA_ALLOWED_ERR            = 6;
const unsigned short      NO_MODIFICATION_ALLOWED_ERR    = 7;
const unsigned short      NOT_FOUND_ERR                  = 8;
const unsigned short      NOT_SUPPORTED_ERR              = 9;
const unsigned short      INUSE_ATTRIBUTE_ERR            = 10;
An integer indicating the type of error generated.
Note: Other numeric codes are reserved for W3C for possible future use.
DOMSTRING_SIZE_ERRHIERARCHY_REQUEST_ERRINDEX_SIZE_ERRINUSE_ATTRIBUTE_ERRINVALID_CHARACTER_ERRNOT_FOUND_ERRNOT_SUPPORTED_ERRNO_DATA_ALLOWED_ERRNO_MODIFICATION_ALLOWED_ERRWRONG_DOCUMENT_ERRThe DOMImplementation interface provides a
      number of methods for performing operations that are independent
      of any particular instance of the document object model. 
The DOM Level 1 does not specify a way of creating a document instance, and hence document creation is an operation specific to an implementation. Future Levels of the DOM specification are expected to provide methods for creating documents directly.
interface DOMImplementation {
  boolean            hasFeature(in DOMString feature, 
                                in DOMString version);
};
hasFeaturefeature of type 
DOMStringversion of type 
DOMStringtrue.
  | 
 
  | 
DocumentFragment is a "lightweight" or
      "minimal" Document object. It is very common to want to be able to
      extract a portion of a document's tree or to create a new fragment of
      a document. Imagine implementing a user command like cut or
      rearranging a document by moving fragments around. It is
      desirable to have an object which can hold such fragments and it
      is quite natural to use a Node for this purpose. While it is
      true that a Document object could fulfill this role, 
      a Document object can potentially be a heavyweight 
      object, depending on the underlying implementation. What is really
      needed for this is a very lightweight object. 
      DocumentFragment is such an object.
Furthermore, various operations -- such as inserting nodes as
      children of another Node -- may take
      DocumentFragment objects as arguments;  this
      results in all the child nodes of the DocumentFragment 
      being moved to the child list of this node.
The children of a DocumentFragment node are zero
      or more nodes representing the tops of any sub-trees defining
      the structure of the document. DocumentFragment nodes do not
      need to be well-formed XML documents (although they do need to
      follow the rules imposed upon well-formed XML parsed entities,
      which can have multiple top nodes). 
      For example, a DocumentFragment might have only one child and
      that child node could be a Text node. Such a structure model 
      represents neither an HTML document nor a well-formed XML document. 
      
When a DocumentFragment is inserted into a 
      Document (or indeed any other Node that may take children)
      the children of the DocumentFragment and not the DocumentFragment 
      itself are inserted into the Node. This makes the DocumentFragment
      very useful when the user wishes to create nodes that are siblings;
      the DocumentFragment acts as the parent of these nodes so that the
      user can use the standard methods from the Node 
      interface, such as insertBefore and 
      appendChild. 
      
interface DocumentFragment : Node {
};
The Document interface represents the entire
      HTML or XML document. Conceptually, it is the root of the
      document tree, and provides the  primary access to the
      document's data.
Since elements, text nodes, comments, processing instructions,
      etc. cannot exist outside the context of a
      Document, the Document interface also
      contains the factory methods needed to create these objects. 
      The Node objects created have a ownerDocument
      attribute which associates them with the Document within whose 
      context they were created.
interface Document : Node {
  readonly attribute DocumentType     doctype;
  readonly attribute DOMImplementation  implementation;
  readonly attribute Element          documentElement;
  Element            createElement(in DOMString tagName)
                                        raises(DOMException);
  DocumentFragment   createDocumentFragment();
  Text               createTextNode(in DOMString data);
  Comment            createComment(in DOMString data);
  CDATASection       createCDATASection(in DOMString data)
                                        raises(DOMException);
  ProcessingInstruction createProcessingInstruction(in DOMString target, 
                                                    in DOMString data)
                                        raises(DOMException);
  Attr               createAttribute(in DOMString name)
                                        raises(DOMException);
  EntityReference    createEntityReference(in DOMString name)
                                        raises(DOMException);
  NodeList           getElementsByTagName(in DOMString tagname);
};
doctype of type DocumentType, readonlyDocumentType)
	associated with 
	this document. For HTML documents as well as XML documents without a
	document type declaration this returns null. The DOM Level
        1 does not support editing the Document Type Declaration.
	docType cannot be altered in any way, including through
	the use of methods inherited from the Node interface, such as
	insertNode or removeNode.
documentElement of type Element, readonly
implementation of type DOMImplementation, readonlyDOMImplementation object that handles this
	document. A DOM application may use objects from multiple 
        implementations.
createAttributecreateCDATASectionCDATASection node whose value  is
	the specified string.data of type 
DOMStringCDATASection contents.| 
 
The new   | 
| 
 NOT_SUPPORTED_ERR: Raised if this document is an HTML document.  | 
createCommentcreateDocumentFragmentDocumentFragment object.
      
| 
 
A new   | 
createElementElement interface, so attributes can
	be specified directly  on the returned object.Attr nodes representing them are automatically created and
	attached to the element.tagName of type 
DOMStringtagName parameter may be provided in any case, 
            but it must be mapped to the canonical uppercase form by 
            the DOM implementation.
        | 
 INVALID_CHARACTER_ERR: Raised if the specified name contains an illegal character.  | 
createEntityReferenceEntityReference object. In addition, if
	the referenced entity is known, the child list of the
	EntityReference node is made the same as that of the
	corresponding Entity node.name of type 
DOMString| 
 
The new   | 
| 
 INVALID_CHARACTER_ERR: Raised if the specified name contains an illegal character. NOT_SUPPORTED_ERR: Raised if this document is an HTML document.  | 
createProcessingInstructionProcessingInstruction node given
	the specified name and data strings.| 
 
The new   | 
| 
 INVALID_CHARACTER_ERR: Raised if the specified target contains an illegal character. NOT_SUPPORTED_ERR: Raised if this document is an HTML document.  | 
createTextNodegetElementsByTagNameThe Node interface is the primary datatype for the
      entire Document Object Model. It represents a single node in the
      document tree. While all objects implementing the
      Node interface expose methods for dealing with
      children, not all objects implementing the Node
      interface may have children. For example, Text
      nodes may not have children, and adding children to such nodes
      results in a DOMException being raised. 
      
The attributes nodeName, nodeValue 
        and attributes are 
	included as a mechanism to get at node information without 
	casting down to the specific derived interface. In cases where 
	there is no obvious mapping of these attributes for a specific
	nodeType (e.g., nodeValue for an Element 
        or attributes 
	for a Comment), this returns null. Note that the 
	specialized interfaces may contain
	additional and more convenient mechanisms to get and set the relevant
	information.
interface Node {
  // NodeType
  const unsigned short      ELEMENT_NODE                   = 1;
  const unsigned short      ATTRIBUTE_NODE                 = 2;
  const unsigned short      TEXT_NODE                      = 3;
  const unsigned short      CDATA_SECTION_NODE             = 4;
  const unsigned short      ENTITY_REFERENCE_NODE          = 5;
  const unsigned short      ENTITY_NODE                    = 6;
  const unsigned short      PROCESSING_INSTRUCTION_NODE    = 7;
  const unsigned short      COMMENT_NODE                   = 8;
  const unsigned short      DOCUMENT_NODE                  = 9;
  const unsigned short      DOCUMENT_TYPE_NODE             = 10;
  const unsigned short      DOCUMENT_FRAGMENT_NODE         = 11;
  const unsigned short      NOTATION_NODE                  = 12;
  readonly attribute DOMString        nodeName;
           attribute DOMString        nodeValue;
                                        // raises(DOMException) on setting
                                        // raises(DOMException) on retrieval
  readonly attribute unsigned short   nodeType;
  readonly attribute Node             parentNode;
  readonly attribute NodeList         childNodes;
  readonly attribute Node             firstChild;
  readonly attribute Node             lastChild;
  readonly attribute Node             previousSibling;
  readonly attribute Node             nextSibling;
  readonly attribute NamedNodeMap     attributes;
  readonly attribute Document         ownerDocument;
  Node               insertBefore(in Node newChild, 
                                  in Node refChild)
                                        raises(DOMException);
  Node               replaceChild(in Node newChild, 
                                  in Node oldChild)
                                        raises(DOMException);
  Node               removeChild(in Node oldChild)
                                        raises(DOMException);
  Node               appendChild(in Node newChild)
                                        raises(DOMException);
  boolean            hasChildNodes();
  Node               cloneNode(in boolean deep)
                                        raises(DOMException);
};
An integer indicating which type of node this is.
Note: Numeric codes up to 200 are reserved to W3C for possible future use.
ATTRIBUTE_NODEAttr.CDATA_SECTION_NODECDATASection.COMMENT_NODEComment.DOCUMENT_FRAGMENT_NODEDocumentFragment.DOCUMENT_NODEDocument.DOCUMENT_TYPE_NODEDocumentType.ELEMENT_NODEElement.ENTITY_NODEEntity.ENTITY_REFERENCE_NODEEntityReference.NOTATION_NODENotation.PROCESSING_INSTRUCTION_NODEProcessingInstruction.TEXT_NODEText node.The values of nodeName, nodeValue,
    and attributes vary according to the node type as follows:
    
| nodeName | nodeValue | attributes | |
| Attr | name of attribute | value of attribute | null | 
| CDATASection | #cdata-section | content of the CDATA Section | null | 
| Comment | #comment | content of the comment | null | 
| Document | #document | null | null | 
| DocumentFragment | #document-fragment | null | null | 
| DocumentType | document type name | null | null | 
| Element | tag name | null | NamedNodeMap | 
| Entity | entity name | null | null | 
| EntityReference | name of entity referenced | null | null | 
| Notation | notation name | null | null | 
| ProcessingInstruction | target | entire content excluding the target | null | 
| Text | #text | content of the text node | null | 
attributes of type NamedNodeMap, readonlyNamedNodeMap containing the
	attributes of this node (if it is an Element) or
	null otherwise. 
childNodes of type NodeList, readonlyNodeList that contains all
	children of this node. If there are no children, this is a
	NodeList containing no nodes.
firstChild of type Node, readonlynull.
lastChild of type Node, readonlynull.
nextSibling of type Node, readonlynull.
nodeName of type DOMString, readonly
nodeType of type unsigned short, readonly
nodeValue of type DOMStringnull, setting it has no effect.
| 
 NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly.  | 
| 
 DOMSTRING_SIZE_ERR: Raised when it would return more
	    characters than fit in a   | 
ownerDocument of type Document, readonlyDocument object associated with this node. This
	is also the Document object used to create new nodes. When
	this node is a Document, this is
	null.
parentNode of type Node, readonlyAttr, Document,
	DocumentFragment, Entity, and
	Notation may have a parent. However, if a	node has just
	been created and not yet added to the tree, or if it has been removed
	from the tree, this is null.
previousSibling of type Node, readonlynull.
appendChildnewChild to the end of the list of
	children of this node. If the newChild is already in the
	tree, it is first removed.newChild of type 
NodeDocumentFragment
        object, the entire contents of the document fragment are moved
	into the child list of this node| 
 The node added.  | 
| 
 HIERARCHY_REQUEST_ERR: Raised if this node is of a type
	that does not allow children of the type of the  WRONG_DOCUMENT_ERR: Raised if  NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.  | 
cloneNodeparentNode is null.).Element copies all attributes and their
        values, including those generated by the XML processor to represent
        defaulted attributes, but this method does not copy any text it
        contains unless it is a deep clone, since the text is contained in a
        child Text node. Cloning an Attribute
        directly, as opposed to be cloned as part of an Element
        cloning operation, returns a specified attribute
        (specified is true). Cloning any other type
        of node simply returns a copy of this node.EntityReference clone are 
        readonly. In addition, clones
        of unspecified Attr nodes are specified. And, cloning
        Document, DocumentType, Entity,
        and Notation nodes is implementation dependent.deep of type 
booleantrue, recursively clone the subtree under the
	specified node; if false, clone only the node itself (and
	its attributes, if it is an Element). 
	| 
 The duplicate node.  | 
| 
 NOT_SUPPORTED_ERR: Raised if this node is a of type
            | 
hasChildNodes
  | 
 
   | 
insertBeforenewChild before the
	existing child node refChild. If
	refChild is null, insert
	newChild at the end of the list of children.newChild is a DocumentFragment
        object, all of its children are inserted, in the same order, before
	refChild. If the newChild is already in the
	tree, it is first removed.| 
 The node being inserted.  | 
| 
 HIERARCHY_REQUEST_ERR: Raised if this node is of a type
	that does not allow children of the type of the  WRONG_DOCUMENT_ERR: Raised if  NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly or if the parent of the node being inserted is readonly. NOT_FOUND_ERR: Raised if   | 
removeChildoldChild from
	the list of children, and returns it.oldChild of type 
Node| 
 The node removed.  | 
| 
 NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. NOT_FOUND_ERR: Raised if   | 
replaceChildoldChild with
	newChild in the list of children, and returns the
	oldChild node.newChild is a DocumentFragment object,
	oldChild is replaced by all of the
	DocumentFragment children, which are inserted in the
	same order. If the newChild is already in the tree, it is
	first removed.| 
 The node replaced.  | 
| 
 HIERARCHY_REQUEST_ERR: Raised if this node is of a type
	that does not allow children of the type of the  WRONG_DOCUMENT_ERR: Raised if  NO_MODIFICATION_ALLOWED_ERR: Raised if this node or the parent of the new node is readonly. NOT_FOUND_ERR: Raised if   | 
The NodeList interface provides the abstraction of an
      ordered collection of nodes, without defining or
      constraining how this collection is implemented. NodeList
      objects in the DOM are live.
The items in the NodeList are accessible via an
      integral index, starting from 0.
    
interface NodeList {
  Node               item(in unsigned long index);
  readonly attribute unsigned long    length;
};
length of type unsigned long, readonlylength-1 inclusive. 
itemindexth item in the collection.
	If index is greater than or equal to the number
	of nodes in the list, this returns null.index of type 
unsigned long| 
 
The node at the   | 
Objects implementing the NamedNodeMap interface are
      used to represent collections of nodes that can be accessed by name. Note
      that NamedNodeMap does not inherit from
      NodeList; NamedNodeMaps are not maintained in
      any particular order. Objects contained in an object implementing
      NamedNodeMap may also be accessed by an ordinal index, but
      this is simply to allow convenient enumeration of the contents of a
      NamedNodeMap, and does not imply that the DOM specifies an
      order to these Nodes. 
interface NamedNodeMap {
  Node               getNamedItem(in DOMString name);
  Node               setNamedItem(in Node arg)
                                        raises(DOMException);
  Node               removeNamedItem(in DOMString name)
                                        raises(DOMException);
  Node               item(in unsigned long index);
  readonly attribute unsigned long    length;
};
NamedNodeMap objects in the DOM are live.
length of type unsigned long, readonly0 to length-1 inclusive. 
getNamedItemitemindexth item in the map.
	If index is greater than or equal to the number
	of nodes in this map, this returns null.index of type 
unsigned long| 
 
The node at the   | 
removeNamedItemname of type 
DOMStringnodeName of the node to remove.| 
 The node removed from this map if a node with such a name exists.  | 
| 
 NOT_FOUND_ERR: Raised if there is no node named
	 NO_MODIFICATION_ALLOWED_ERR: Raised if this map is readonly.  | 
setNamedItemnodeName attribute. If a node with
        that name is already present in this map, it is replaced by the new
        one.nodeName attribute is used to
	derive the name which the node must be stored under, multiple
	nodes of certain types (those that have a "special" string
	value) cannot be stored as the names would clash. This is seen
	as preferable to allowing nodes to be aliased.arg of type 
NodenodeName
            attribute.| 
 WRONG_DOCUMENT_ERR: Raised if  NO_MODIFICATION_ALLOWED_ERR: Raised if this map is readonly. INUSE_ATTRIBUTE_ERR: Raised if   | 
The CharacterData interface extends Node with a set 
      of attributes and methods for accessing character data in the DOM. For
      clarity this set is defined here rather than on each object that uses
      these attributes and methods. No DOM objects correspond directly to
      CharacterData, though Text and others do
      inherit the interface from it. All offsets in this
      interface start from 0.
As explained in the DOMString interface, text strings
          in the DOM are represented in UTF-16, i.e. as a sequence of 16-bit
          units.  In the following, the term 16-bit units is used whenever
          necessary to indicate that indexing on CharacterData is done in
          16-bit units.
interface CharacterData : Node {
           attribute DOMString        data;
                                        // raises(DOMException) on setting
                                        // raises(DOMException) on retrieval
  readonly attribute unsigned long    length;
  DOMString          substringData(in unsigned long offset, 
                                   in unsigned long count)
                                        raises(DOMException);
  void               appendData(in DOMString arg)
                                        raises(DOMException);
  void               insertData(in unsigned long offset, 
                                in DOMString arg)
                                        raises(DOMException);
  void               deleteData(in unsigned long offset, 
                                in unsigned long count)
                                        raises(DOMException);
  void               replaceData(in unsigned long offset, 
                                 in unsigned long count, 
                                 in DOMString arg)
                                        raises(DOMException);
};
data of type DOMStringCharacterData node. However, implementation limits may 
	mean that the entirety of a node's data may not fit into a single
	DOMString. In such cases, the user may call
	substringData to retrieve the data in appropriately sized
	pieces.
| 
 NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly.  | 
| 
 DOMSTRING_SIZE_ERR: Raised when it would return more
	    characters than fit in a   | 
length of type unsigned long, readonlydata and the
    substringData method below.  This may have the value zero, 
    i.e., CharacterData nodes may be empty.
appendDatadata provides access to the concatenation of
	data and the DOMString specified. 
| 
 NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.  | 
deleteDatadata and length reflect the change.offset of type 
unsigned longcount of type 
unsigned longoffset and count exceeds
	length then all 16-bit units from offset
	to the end of the data are deleted.
| 
 INDEX_SIZE_ERR: Raised if the specified  NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.  | 
insertData
| 
 INDEX_SIZE_ERR: Raised if the specified  NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.  | 
replaceDataoffset of type 
unsigned longcount of type 
unsigned longoffset and count exceeds
	    length, then all 16-bit units to the end of the data
	    are replaced; (i.e., the effect is the same as a
	    remove method call with the same range, followed
	    by an append method invocation).arg of type 
DOMStringDOMString with which the range must
	    be replaced.
| 
 INDEX_SIZE_ERR: Raised if the specified  NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.  | 
substringDataoffset of type 
unsigned longcount of type 
unsigned long| 
 
The specified substring. If the sum of   | 
| 
 INDEX_SIZE_ERR: Raised if the specified  DOMSTRING_SIZE_ERR: Raised if the specified range of text does
	not fit into a   | 
The Attr interface represents an attribute in an Element object.
Typically the allowable values for the attribute are defined in a document
type definition.
Attr objects inherit the Node 
   interface, but since they are not actually child nodes of the element 
   they describe, the DOM does not consider them part of the document 
   tree.  Thus, the Node attributes parentNode, 
   previousSibling, and nextSibling have a 
   null value for Attr objects. The DOM takes the 
   view that attributes are properties of elements rather than having a 
   separate identity from the elements they are associated with; 
   this should make it more efficient to implement
   such features as default attributes associated with all elements of a 
   given type.  Furthermore, Attr
   nodes may not be immediate children of a DocumentFragment.
   However, they can be associated with Element nodes contained within
   a DocumentFragment.
   In short, users and implementors of the DOM need to be aware that 
   Attr nodes have some things in 
   common with other objects inheriting the Node interface, 
   but they also are quite distinct.
 The attribute's effective value is determined as follows: if this 
   attribute has been explicitly assigned any value, that value is the 
   attribute's effective value; otherwise, if there is a declaration for 
   this attribute, and that declaration includes a default value, then 
   that default value is the attribute's effective value; otherwise, the 
   attribute does not exist on this element in the structure model until 
   it has been explicitly added.  Note that the nodeValue 
   attribute on the Attr instance can also be used to
   retrieve the string version of the attribute's value(s). 
In XML, where the value of an attribute can contain entity references,
    the child nodes of the Attr node provide a representation in
    which entity references are not expanded. These child nodes may be either
    Text or EntityReference nodes. Because the
    attribute type may be unknown, there are no tokenized attribute values.
    
interface Attr : Node {
  readonly attribute DOMString        name;
  readonly attribute boolean          specified;
  // Modified in DOM Level 1:
           attribute DOMString        value;
                                        // raises(DOMException) on setting
};
name of type DOMString, readonly
specified of type boolean, readonlytrue; otherwise, it is false.
    Note that the implementation is in charge of this attribute, not the
    user. If the user changes the value of the attribute (even if it ends up
    having the same value as the default value) then the specified
    flag is automatically flipped to true.  To re-specify the
    attribute as the default value from the DTD, the user must delete the
    attribute. The implementation will then make a new attribute available
    with specified set to false and the default value
    (if one exists).specified is true, and the value is the 
    assigned value.
specified is false,  
    and the value is the default value in the DTD.specified is true.
value of type DOMString, modified in DOM Level 1getAttribute on the 
        Element interface.Text node with the unparsed
	contents of the string. I.e. any characters that an XML processor would
        recognize as markup are instead treated as literal text.
	See also the method setAttribute on the 
        Element interface.
| 
 NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly.  | 
The Element interface represents an element in an HTML
    or XML document. Elements may have attributes associated with them; since the
    Element interface inherits from Node, the generic
    Node interface attribute attributes may be used
    to retrieve the set of all attributes for an element.  There are methods on
    the Element interface to retrieve either an Attr
    object by name or an attribute value by name. In XML, where an attribute
    value may contain entity references, an Attr object should be
    retrieved to examine the possibly fairly complex sub-tree representing the
    attribute value. On the other hand, in HTML, where all attributes have
    simple string values, methods to directly access an attribute value can
    safely be used as a convenience.
interface Element : Node {
  readonly attribute DOMString        tagName;
  DOMString          getAttribute(in DOMString name);
  void               setAttribute(in DOMString name, 
                                  in DOMString value)
                                        raises(DOMException);
  void               removeAttribute(in DOMString name)
                                        raises(DOMException);
  Attr               getAttributeNode(in DOMString name);
  Attr               setAttributeNode(in Attr newAttr)
                                        raises(DOMException);
  Attr               removeAttributeNode(in Attr oldAttr)
                                        raises(DOMException);
  NodeList           getElementsByTagName(in DOMString name);
  void               normalize();
};
tagName of type DOMString, readonly
<elementExample id="demo"> 
        ... 
</elementExample> ,
tagName has the value
     "elementExample". Note that this is
     case-preserving in XML, as are all of the operations of the DOM.
     The HTML DOM returns the tagName of an HTML element
     in the canonical uppercase form, regardless of the case in the 
     source HTML document. 
getAttributegetAttributeNodegetElementsByTagNameNodeList of all descendant Elements with a
	given tag name, in the order in which they would be encountered in a
	preorder traversal of the Element tree.name of type 
DOMString| 
 
A list of matching   | 
normalizeText nodes in the full depth of the
        sub-tree underneath this Element, including attribute
	nodes, into a "normal" form where only markup (e.g., tags, comments,
	processing instructions, CDATA sections, and entity references)
	separates Text nodes, i.e., there are no adjacent
	Text nodes.  This can be used to ensure that the DOM view
	of a document is the same as if it were	saved and re-loaded, and is
	useful when operations (such as XPointer [XPointer]
	lookups) that depend on a particular document tree structure are to be
	used.Note: In cases where the document contains CDATASections, the
	  normalize operation alone may not be sufficient, since XPointers
	  do not differentiate between Text nodes and
	  CDATASection nodes.
removeAttributename of type 
DOMString
| 
 NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.  | 
removeAttributeNodeAttr has a default value it is immediately replaced. 
 
| 
 NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. NOT_FOUND_ERR: Raised if   | 
setAttributeAttr node plus any Text and
      EntityReference nodes, build the appropriate subtree, and
      use setAttributeNode to assign it as the value of an
      attribute.
| 
 INVALID_CHARACTER_ERR: Raised if the specified name contains an illegal character. NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.  | 
setAttributeNode| 
 WRONG_DOCUMENT_ERR: Raised if  NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. INUSE_ATTRIBUTE_ERR: Raised if   | 
The Text interface inherits from
      CharacterData and represents the textual
      content (termed 
character 
      data in XML) of an Element or Attr. 
      If there is no markup inside an element's content, the text is contained
      in a single object implementing the Text interface that
      is the only child of the element. If there is markup, it is parsed into
      the information items (elements, 
      comments, etc.) and Text 
      nodes that form the list of children of the element.
When a document is first made available via the DOM, there is 
      only one Text node for each block of text. Users may create 
      adjacent Text nodes that represent the 
      contents of a given element without any intervening markup, but
      should be aware that there is no way to represent the separations
      between these nodes in XML or HTML, so they will not (in general)
      persist between DOM editing sessions. The normalize()
      method on Element merges any such adjacent Text
      objects into a single node for each block of text.
interface Text : CharacterData {
  Text               splitText(in unsigned long offset)
                                        raises(DOMException);
};
splitTextoffset, keeping both in the tree as
	siblings. This node then only contains all the content up to the
	offset point. A new node of the same type, which is
	inserted as the next sibling of this node, contains all the content at
	and after the offset point. When the offset
	is equal to the length of this node, the new node has
	no data.offset of type 
unsigned long0.| 
 The new node, of the same type as this node.  | 
| 
 INDEX_SIZE_ERR: Raised if the specified offset is negative or
	greater than the number of 16-bit units in  NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.  | 
This interface inherits from CharacterData and
      represents the content of a comment, i.e., all the
      characters between the starting '<!--' and
      ending '-->'. Note that this is the definition
      of a comment in XML, and, in practice, HTML, although some HTML
      tools may implement the full SGML comment structure.
interface Comment : CharacterData {
};
The interfaces defined here form part of the DOM Level 1 Core specification, but objects that expose these interfaces will never be encountered in a DOM implementation that deals only with HTML. As such, HTML-only DOM implementations do not need to have objects that implement these interfaces.
A DOM application can use the hasFeature method of the 
      DOMImplementation interface to determine whether they
      are supported or not. The feature string for all the interfaces listed in
      this section is "XML" and the version is "1.0".
CDATA sections are used to escape blocks of text containing characters that would otherwise be regarded as markup. The only delimiter that is recognized in a CDATA section is the "]]>" string that ends the CDATA section. CDATA sections cannot be nested. Their primary purpose is for including material such as XML fragments, without needing to escape all the delimiters.
The DOMString attribute of the
      Text node holds the text that is contained by the CDATA
      section. Note that this may contain characters
      that need to be escaped outside of CDATA sections and that, depending on
      the character encoding ("charset") chosen for serialization, it may be
      impossible to write out some characters as part of a CDATA section.
The CDATASection interface inherits from the
      CharacterData interface through the Text
      interface. Adjacent CDATASection nodes are not merged by
      use of the normalize method on the Element interface.
Note: Because no markup is recognized within a CDATASection,
	character numeric references cannot be used as an escape mechanism
	when serializing. Therefore, action needs to be taken when serializing
	a CDATASection with a character encoding where some of
	the contained characters cannot be represented. Failure to do so would
	not produce well-formed XML.
One potential solution in the serialization process is to end the
	CDATA section before the character, output the character using a 
	character reference or entity reference, and open a new CDATA section 
	for any further characters in the text node. Note, however, that some 
	code conversion libraries at the time of writing do not return an
	error or exception when a character is missing from the encoding, 
	making the task of ensuring that data is not corrupted on serialization
	more difficult.
interface CDATASection : Text {
};
Each Document has a doctype attribute
        whose value is either null or a DocumentType
        object. The DocumentType interface in the DOM Level 1 Core
      provides an interface to the list of entities that are defined
      for the document, and little else because the effect of
      namespaces and the various XML scheme efforts on DTD
      representation are not clearly understood as of this writing.
The DOM Level 1 doesn't support editing DocumentType
      nodes.
interface DocumentType : Node {
  readonly attribute DOMString        name;
  readonly attribute NamedNodeMap     entities;
  readonly attribute NamedNodeMap     notations;
};
entities of type NamedNodeMap, readonlyNamedNodeMap containing the general entities, both
	external and internal, declared in the DTD. Parameter entities are not
	contained. Duplicates are discarded.
	For example in:
<!DOCTYPE ex SYSTEM "ex.dtd" [ <!ENTITY foo "foo"> <!ENTITY bar "bar"> <!ENTITY bar "bar2"> <!ENTITY % baz "baz"> ]> <ex/>
foo and the first
	declaration of bar but not the second declaration of 
        bar or baz. Every node in this map
	also implements the Entity interface.entities cannot be altered in any way.
name of type DOMString, readonlyDOCTYPE keyword.
notations of type NamedNodeMap, readonlyNamedNodeMap containing  the
	notations declared in the DTD. Duplicates are discarded. Every node in
	this map also implements the Notation interface.notations cannot be altered in any way.
This interface represents a notation declared in the DTD. A notation
      either declares, by name, the format of an unparsed entity (see 
section 4.7
      of the XML 1.0 specification [XML]), or is used for formal
      declaration of
    processing instruction targets (see 
section 2.6 of the XML 1.0
      specification [XML]). The nodeName attribute
      inherited from
    Node is set to the declared name of the notation.
The DOM Level 1 does not support editing Notation
     nodes; they are therefore
     readonly.
A Notation node does not have any parent.
interface Notation : Node {
  readonly attribute DOMString        publicId;
  readonly attribute DOMString        systemId;
};
This interface represents an entity, either parsed or
      unparsed, in an XML document. Note that this models the entity
      itself not the entity declaration. Entity
      declaration modeling has been left for a later Level of the DOM
      specification.
The nodeName attribute that is inherited from
      Node contains the name of the entity.
An XML processor may choose to completely expand entities before 
      the structure model is passed to the DOM; in this case there will
      be no EntityReference nodes in the document tree.
XML does not mandate that a non-validating XML processor read
      and process entity declarations  made in the external subset or
      declared in external parameter entities. This means
      that parsed entities declared in the external subset
      need not be expanded by some classes of applications, and that
      the replacement value of the entity may not be available. When the
      replacement value is available, the corresponding 
      Entity node's child list represents the structure of
      that replacement text. Otherwise, the child list is empty.
The resolution of the children of the Entity (the 
      replacement value) may be lazily evaluated; actions by the user (such as
      calling the childNodes method on the
      Entity Node) are assumed to trigger the evaluation. 
    
The DOM Level 1 does not support editing Entity
      nodes; if a user wants to make changes to the contents of an
      Entity, every related EntityReference node
      has to be replaced in the structure model by a clone of the
      Entity's contents, and then the desired changes must be made
      to each of those clones instead. Entity nodes and all their
      descendants are readonly.
An Entity node does not have any parent.
interface Entity : Node {
  readonly attribute DOMString        publicId;
  readonly attribute DOMString        systemId;
  readonly attribute DOMString        notationName;
};
notationName of type DOMString, readonlynull. 
publicId of type DOMString, readonlynull.
systemId of type DOMString, readonlynull.
      EntityReference objects may be inserted into the
      structure model when an entity reference is in the source document,
      or when the user wishes to insert an entity reference. Note that 
      character references and references to predefined entities are
      considered to be expanded by the HTML or XML
      processor so that characters are represented by their Unicode
      equivalent rather than by an entity reference. Moreover, the XML 
      processor may completely expand references to entities while building the
      structure model, instead of providing EntityReference
      objects. If it does provide such objects, then for a given
      EntityReference node, it may be that there is no
      Entity node representing the referenced entity.
      If such an Entity exists, then the child list of the
      EntityReference node is the same as that of the
      Entity node.
As for Entity nodes, EntityReference nodes and
      all their descendants are
      readonly.
The resolution of the children of the EntityReference (the 
      replacement value of the referenced Entity) may be lazily 
      evaluated; actions by the user (such as calling the 
      childNodes method on the EntityReference node) 
      are assumed to trigger the evaluation.
interface EntityReference : Node {
};
The ProcessingInstruction interface
      represents a  "processing instruction", used in XML
      as a way to keep processor-specific information in the text of the
      document.
interface ProcessingInstruction : Node {
  readonly attribute DOMString        target;
           attribute DOMString        data;
                                        // raises(DOMException) on setting
};
data of type DOMString?>.
| 
 NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly.  | 
target of type DOMString, readonly