100分！ajax请求错误

C# code:

<script type="text/javascript">
window.onload=function()
{
startRequest('get','../College.ashx','lxyc=2&time='+new Date().getTime()+'',ShowIt,true);


}
var xmlHttp1;
function createXMLRequest()
{
if(window.ActiveXObject)
{
xmlHttp1=new ActiveXObject("Microsoft.XMLHTTP");
}
else if(window.XMLHttpRequest)
{
xmlHttp1=new XMLHttpRequest();
}
else

{
alert("不能创建XMLHttpRequest");
}
}
function startRequest(method,url,pars,callbackfun,cache)
{
// alert(method+url+pars+callbackfun+cache);
if(typeof callbackfun != 'function'){
alert('The CallBackFun is not a function!');
}
if(cache){
pars += "&tmp="+Math.random();
}
createXMLRequest();
xmlHttp1.onreadystatechange = function(){
if(xmlHttp1.readyState==4)
{
if(xmlHttp1.status==200)
{
callbackfun(xmlHttp1);
xmlHttp1.abort();
}
else
{
xmlHttp1.abort();