function CreateAjaxObject(){
var ajaxObject=false;
var is_ie5 = (navigator.appVersion.indexOf("MSIE 5.5")!=-1) ? 1 : 0;
var strObjName = (is_ie5) ? 'Microsoft.XMLHTTP' : 'Msxml2.XMLHTTP'; 
try{
ajaxObject = new ActiveXObject(strObjName);
} catch (e){
ajaxObject = false;
}
if (!ajaxObject && typeof XMLHttpRequest!='undefined') {
try {
ajaxObject = new XMLHttpRequest();
} catch (e) {
ajaxObject=false;
}
}
if (!ajaxObject && window.createRequest) {
try{
ajaxObject = window.createRequest();
}catch (e){
ajaxObject=false;
}
}
return ajaxObject
}

function CreateRequest(){
this.ajaxObject = CreateAjaxObject();
}