//创建XMLHttpRequest对象
var _Global_XMLHttpReq;
function CreateXMLHttpRequest()
{
    _Global_XMLHttpReq = null;
    if(window.XMLHttpRequest)
    {
        _Global_XMLHttpReq = new XMLHttpRequest();
    }
    else if(window.ActiveXObject)
    {
        try
        {
            _Global_XMLHttpReq = new ActiveXObject("Msxml2.XMLHTTP");
        }
        catch(e)
        {
            try
            {
                _Global_XMLHttpReq = new ActiveXObject("Microsoft.XMLHTTP");
            }
            catch(e)
            {
            }
        }
    }
}