var uaString = navigator.userAgent.toLowerCase();
var isOpera = uaString.indexOf("opera") != -1;
var isIE = uaString.indexOf("msie") != -1 && (document.all && !isOpera);
var isIE5 = isIE && uaString.indexOf("msie 5") != -1;
var isIE6 = isIE && uaString.indexOf("msie 6") != -1;
var isKonqueror = uaString.indexOf("konqueror") != -1;
var isSafari = uaString.indexOf("safari") != -1 || isKonqueror;
var isCamino = uaString.indexOf("camino") != -1;
var isGecko = !isIE && (!isSafari && (uaString.indexOf("mozilla") != -1 || isOpera));
var isMacintoshOS = uaString.indexOf("macintosh") != -1;
var isLinuxOS = uaString.indexOf("linux") != -1;
var isWinXPOS = uaString.indexOf("windows nt 5.1") != -1 || uaString.indexOf("windows xp") != -1;
var isWin2kOS = uaString.indexOf("windows nt 5.0") != -1 || uaString.indexOf("windows 2000") != -1;
var isWinNTOS = isWinXPOS || isWin2kOS;

function GeneralXMLHttpRequest()
{
    var req = null;

    if(isIE){
        var className = isIE5 ? "Microsoft.XMLHTTP" : "Msxml2.XMLHTTP";
        try {
            req = new ActiveXObject(className)
        }catch(c){
            //q(c);
            alert("You need to enable active scripting and activeX controls.")
        }
    } else {
        req = new XMLHttpRequest();
        if(!req) {
            alert("XMLHttpRequest is not supported on this browser.")
        }
    }
    return req
}