<!DOCTYPE html>
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>aria-describedby example 1: Add description to close button</title>

</head>

<body>

<button aria-label="Close window" aria-describedby="descriptionClose"
onclick="myDialog.close()">X</button>
<p>other content</p>
<div id="descriptionClose">Closing this window will discard any information entered and return you back to the main page</div>

</body>
</html>