简单的不能再简单的AJAX原型调了1天了，还是只执行一次回调，请帮忙解决！
test.asp 
<script> 
var xmlHttpWL = false; 
try { 
  xmlHttpWL = new ActiveXObject("Msxml2.XMLHTTP"); 
} catch (e) { 
  try { 
  xmlHttpWL = new ActiveXObject("Microsoft.XMLHTTP"); 
  } catch (e2) { 
  xmlHttpWL = false; 
  } 
} 
if (!xmlHttpWL && typeof XMLHttpRequest != 'undefined') { 
  xmlHttpWL = new XMLHttpRequest(); 
} 
var xmlHttpWL01 = false; 
try { 
  xmlHttpWL01 = new ActiveXObject("Msxml2.XMLHTTP"); 
} catch (e) { 
  try { 
  xmlHttpWL01 = new ActiveXObject("Microsoft.XMLHTTP"); 
  } catch (e2) { 
  xmlHttpWL01 = false; 
  } 
} 
if (xmlHttpWL01 && typeof XMLHttpRequest != 'undefined') { 
  xmlHttpWL01 = new XMLHttpRequest(); 
} 


function add() 
{ 
url = "Test_duibi.asp?action=setstr&pname="+document.getElementsByName("pname")[0].value; 
xmlHttpWL.open("GET", url, true); 
xmlHttpWL.send(null);  
} 
function get() 
{ 
url = "Test_duibi.asp"; 
xmlHttpWL01.onreadystatechange = setTable; 
xmlHttpWL01.open("GET", url+"?t="+Math.random(), true); 
xmlHttpWL01.send(null);  
} 

function setTable() 
{ 

  if (xmlHttpWL01.readyState == 4) 
  { 
if (xmlHttpWL01.status == 200) 
{ 
var ss = xmlHttpWL01.responseText; 
alert(ss); 
} 
  } 
} 
</script> 
<INPUT TYPE="text" NAME="pname" > <INPUT TYPE="button" value="set" onclick="add();"> <INPUT TYPE="button" value="get" onclick="get();"> 
<% 
response.write("Cookies="&Request.Cookies("WL_DuiBi")) 
%> 
================================ 
Test_duibi.asp 
==================== 
<%@ LANGUAGE = VBScript codepage=65001%> 
<% 
response.charset="utf-8" 
Response.Buffer = True  
response.expires=0  
Response.CacheControl="no-cache "  
Response.AddHeader "Pragma","no-cache"  

Select Case request("action") 
  Case "setstr" : setstr() 
  Case Else 
getstr() 
End Select  
Sub setstr() 
response.cookies("WL_DuiBi")=Trim(request("pname")) 
End Sub  

Sub getstr() 
response.write(Request.Cookies("WL_DuiBi")) 
End Sub  
%> 

======================= 
所有功能实现都没有问题，就是只回调一次，即使不用COOKICES，换成返回随机数或数据库内容也只回调一次， 
还试过一个 xmlHttpWL01.abort(); 的也不行， 缓存也清了，url也加了随即参数，但还是不行，请教？

------解决方案--------------------
其实你可以写成

JScript code

function cXML(){
    var objXML=null,xmlStr
    if(window.ActiveXObject){
        var xmlStr=ne