var aXmlHttp = new Array();
var aXmlResponse = new Array();
var httpRequest = null;
var fn = ob = null;
function xmlResult()
{
    //alert("phan1" + aXmlHttp.length);
    for (var i = 0; i < aXmlHttp.length; i++)
    {
        if (aXmlHttp[i] && aXmlHttp[i][0] && aXmlHttp[i][0].readyState == 4 && aXmlHttp[i][0].responseText)
        {
            if (aXmlHttp[i][0].status == 200) {
                //must null out record before calling function in case
                //function invokes another xmlHttpRequest.

                var f = aXmlHttp[i][2];
                var o = aXmlHttp[i][1];
                var s = aXmlHttp[i][0].responseText;
                aXmlHttp[i][0] = null;
                aXmlHttp[i][1] = null;
                aXmlHttp[i][2] = null;
                f.apply(o, new Array(s));
            }

        }

    }
}

// u -> url
// o -> object (can be null) to invoke function on
// f -> callback function
// p -> optional argument to specify POST

function call(u, o, f)
{
    var method = "GET";
    var dat;
    if (arguments.length == 4) {
        method = "POST";
        tmp = u.split(/\?/);
        u = tmp[0];
        dat = tmp[1];

    }
    var idx = aXmlHttp.length;
    for (var i = 0; i < idx; i++)
        if (aXmlHttp[i] == null)
        {
            idx = i;
            break;
        }

    aXmlHttp[idx] = new Array(10);

    aXmlHttp[idx][0] = getXMLHTTP();

    aXmlHttp[idx][1] = o;
    aXmlHttp[idx][2] = f;
    if (aXmlHttp[idx])
    {
        aXmlHttp[idx][0].open(method, u, true);
        if (method == "POST") {
            aXmlHttp[idx][0].setRequestHeader("Content-Type", "application/x-www-form-urlencoded;charset=UTF-8; text/xml");
            aXmlHttp[idx][0].send(dat);
        }
        aXmlHttp[idx][0].onreadystatechange = xmlResult;
        if (method == "GET") {
            aXmlHttp[idx][0].send(null);
        }
    }
    //alert("111");
}


function getXMLHTTP()
{
    var A = null;
    if (!A && typeof XMLHttpRequest != "undefined")
    {
        A = new XMLHttpRequest();
        if (A.overrideMimeType) {
            A.overrideMimeType('text/xml');
        }

    }
    if (!A)
    {
        try
        {
            A = new ActiveXObject("Msxml2.XMLHTTP");
        }
        catch(e)
        {
            try
            {
                A = new ActiveXObject("Microsoft.XMLHTTP");
            }
            catch(oc)
            {
                A = null
            }
        }
    }
    return A;
}