function GetXmlHttpObject(handler)
{ 
    var objXmlHttp=null;

    if (navigator.userAgent.indexOf("Opera")>=0)
    {
    alert("This example doesn't work in Opera") 
    return; 
    }
    if (navigator.userAgent.indexOf("MSIE")>=0)
    { 
            var strName="Msxml2.XMLHTTP"
            if (navigator.appVersion.indexOf("MSIE 5.5")>=0)
            {
            strName="Microsoft.XMLHTTP"

            } 
            try
            { 
            objXmlHttp=new ActiveXObject(strName);
            objXmlHttp.onreadystatechange=handler;
            return objXmlHttp;
            } 
            catch(e)
            { 
            alert("Error. Scripting for ActiveX might be disabled");
            return;
            } 
    } 
    if (navigator.userAgent.indexOf("Mozilla")>=0)
    {
        objXmlHttp=new XMLHttpRequest()
        objXmlHttp.onload=handler
        objXmlHttp.onerror=handler 
        return objXmlHttp;
    }
}