XMLHttpRequest（）。Open不是firefox中的函数，但适用于chrome

Question

I have the function below but when I try to run it in firefox i get the error "xmlhttp.Open is not a function" this does not happen in google chrome however have I missed some code converting from the ActiveXObject? The PAGE parameter is set and works for the ActiveXObject in Internet Explorer

    function broker(PAGE,PARAMARR,STARTPARAM)
    {
        var postdata=getPostData();
        var ua=navigator.userAgent;
        var msie=ua.indexOf ('MSIE ');
        //var xmlhttp =null;
        if (msie!=-1)
        {
            xmlhttp = new ActiveXObject('MSXML2.XMLHTTP');
            xmlhttp.Open('POST',PAGE,false);
            xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
        } 
        else {
            xmlhttp = new XMLHttpRequest();
            xmlhttp.Open('POST',PAGE,false);
            xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
        }
        var paramno,param;
        for (paramno=STARTPARAM;paramno<PARAMARR.length;paramno++)
        {
            param=PARAMARR[paramno];if (param==void 0) param='';
            if (param===true) param=-1;
            if (param===false) param=0;
            postdata=postdata+'&Parameter='+encodeURIComponent(param);
        }
        xmlhttp.setRequestHeader('Content-Length', postdata.length);
        xmlhttp.send(postdata);
        var response=new String(xmlhttp.responseText);
        var brkmsg=getMessage(response);
        return brkmsg;
}

Chrome: Netscape mozilla/5.0 (windows nt 6.1; wow64) applewebkit/537.36 (khtml, like gecko) chrome/47.0.2526.106 safari/537.36

Firefox: Netscape mozilla/5.0 (windows nt 6.1; wow64; rv:43.0) gecko/20100101 firefox/43.0

IE11: Netscape mozilla/5.0 (windows nt 6.1; wow64; trident/7.0; slcc2; .net clr 2.0.50727; .net clr 3.5.30729; .net clr 3.0.30729; media center pc 6.0; .net4.0c; .net4.0e; infopath.3; rv:11.0) like gecko)

IE8 (Compatability Mode): Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.2; WOW64; Trident/4.0; .NET CLR 3.0.4506.2152; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET4.0C; .NET4.0E; InfoPath.2)

Answer 1

Seems to be a typo. Write "open" in lower case!