I am trying to create a basic Ajax interaction on my page. I send an XMLHTTPRequest to and ASP page and it returns well-formed xml. I am getting the results I expect when I view the xmlhttp.ResponseText, but I cannot get the xmlhttpResponseXML to work with Javascript. Here is some of the code, I only want to use a JS xml object to set the root element and navigate through the object using the DOM (childNodes, nodeValue, etc.)

xmlhttp.responseText (XML returned from asp page):

<?xml version="1.0" encoding="iso-8859-1"?>
<root>
<escalation>
<author>George Bush</author>
<creationdate>2006-06-05 14:59:04</creationdate>
<recordnumber>E-04805</recordnumber>
<client>Acme</client>
<businesscase>Acme is making major changes to their internal processes. One of the biggest changes is to move the users from Excel to Analysis & Reporting. This enhancement strengthens their case for moving to A&R, and during Acme's recent visit we indicated to Acme that this change would be fairly easy to implement.</businesscase>
</escalation>

<escalation>
<author>Bubba SMith</author>
<creationdate>2006-07-06 12:09:02</creationdate>
<recordnumber>E-04805</recordnumber>
<client>Ace</client>
<businesscase>This is a key element in Ace's strategy to move their users to A&R, and they continue to inquire as to the status of this enhancement request. Can you give me an idea as to when this will be addressed?
</businesscase>
</escalation>
</root>


Ajax Functions:

function processxmlhttpChange()
{
if ((xmlhttp.readyState == 4) && (xmlhttp.status == 200))
{
alert(xmlhttp.responseText); //Returns XML as shown above
rootElement = xmlhttp.responseXML.getElementsByTagName("root")[0];
alert(rootElement.childNodes[0].tagName);
}
}


function getAll(recordNo)
{
//Create the urls to retreive data
issueURL = "/allEscByRecord.asp?rn=" + recordNo

//Create XML object and send request
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
xmlhttp.open("GET", issueURL, true);
xmlhttp.onreadystatechange = processxmlhttpChange;
xmlhttp.send();
}