Javascript XML Parsing

//Create a XMLDoc object from the xml string.

function getXMLDocObject(xmlstr) {
 var xmlDoc;
 try { //Internet Explorer
   try {
     xmlDoc=new ActiveXObject("MSXML2.DOMDocument"); 
   } catch(e) {
     xmlDoc=new ActiveXObject("Microsoft.XMLDOM");
   }
   xmlDoc.async="false";
   xmlDoc.loadXML(xmlstr);
 } catch(e) {
   try { //Firefox, Mozilla, Opera, etc.
     parser=new DOMParser();
     xmlDoc=parser.parseFromString(xmlstr,"text/xml");
   } catch(e) {
     alert(e.message)
   }
 }
 return xmlDoc;
}

/* Consider the following XML

<?xml version="1.0" encoding="utf-8"?>
<rootnode>
 <error value='true'>
   <message>this is the message</message>
 </error>
</rootnode>

*/

// Create XMLDoc object
xmlDoc = getXMLDocObject(asyncreq.responseText);

// Get root node
var root = xmlDoc.getElementsByTagName('rootnode')[0];

/* You can loop over all child nodes of root using root.childNodes and root.childNodes.length */

// Will alert "error"
alert(root.childNodes[1].nodeName);

// Will alert "true";
alert(root.childNodes[1].getAttribute('value'));

// Will alert "message";
alert(root.childNodes[1].childNodes[1].nodeName);

// Will alert "this is the message".
alert(root.childNodes[1].childNodes[1].childNodes[0].nodeValue);