Copyright: Copyright 1998-2001 W3C (MIT, INRIA, Keio), All Rights Reserved.
See http://www.w3.org/Consortium/Legal/.
Author: Warner ten Kate (warner.ten.kate@philips.com), modified by Erik Hodge, RealNetworks
           Version: Mar 26, 2001, v2
            Module: SMIL Structure Module
           Feature: systemRequired on <smil> element
         File Name: Structure_systemRequired.smil
  Media Components: 3 JPG
 Expected Behavior: If the Obscure module is not supported, the document is not shown.
<smil xmlns="http://www.w3.org/2001/SMIL20/Language" 
      systemRequired="Obscure" >
         <region id="r1" top="0px" left="0px" height="240px" width="320px" />
         <img dur="5s" src="../images/frown.jpg"  region="r1"/>
         <img dur="5s" src="../images/smile.jpg" region="r1"/>