sgmlreader

Why does XmlDocument.GetElementById always return null?

I've got some XML (valid XHTML) that looks like this: <html> <head> <script type="text/javascript"><![CDATA[ function change_header() { document.getElementById("myHeader").innerHTML="Nice day!"; } ]]></script> </head> <body> <h1 id="myHeader">Hello World!</h1> <button onclick="change_header()">Change text</button> </body> </html> A...