Hi,I create a simple module.Code as follows:

<%@ Control Language="VB" AutoEventWireup="false" CodeFile="ViewEvaResult.ascx.vb" Explicit="True" Inherits="ZAMAM.Modules.Z_EduEvaluate.ViewEvaResult" %>
<script  type="text/javascript" >
    var xmlHttp;
    function createXMLHttpRequest()
        {
            if (window.ActiveXObject)
            {
                xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
            }  
            else if (window.XMLHttpRequest)
                {
                    xmlHttp=new XMLHttpRequest();
                }   
        }
    function startRequest()
    {
        alert('Please select at least one exception.');
        createXMLHttpRequest();
        xmlHttp.onreadystatechange=handleStateChange;
        xmlHttp.open("GET","innerHTML.xml",true);
        xmlHttp.send(null);    
        }
  function handleStateChange()
   {
        alert("1");
        if (xmlHttp.readyState==4)
        {
            alert("2");
            if (xmlHttp.status==200)
            {
                alert("3");
                document.getElementById("results").innerHTML="Hello";
            }
        }
   }       
   </script>
   <asp:Panel ID="test" runat="server">
   <input type="button" value="Test" onclick="startRequest();" /><br />
   <div id="results"></div>
   </asp:Panel>

When IE first load the page that includes this module,there is a "Hello" string in the page after clicking the button.Very good!But after Roloading the page or logining the website,these is not "Hello" forever after clicking the button.What I can see just some alerts that have value "1" or "2".Why it doesn't excute code:

alert("3");
document.getElementById("results").innerHTML="Hello";