function sendRequest(url, callback, postData) {

    d = new Date();
    url = url + '&cache=' + d.getTime().toString();
    var req = createXMLHTTPObject();
    if (!req) return;

    var method = (postData) ? "POST" : "GET";
    req.open(method, url, true);
    req.setRequestHeader('User-Agent', 'XMLHTTP/1.0');

    if (postData)
        req.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');

    req.onreadystatechange = function () {
        if (req.readyState != 4) return;
        if (req.status != 200 && req.status != 304) {
            return;
        }
        callback(req);
    }

    if (req.readyState == 4) {
        return;
    }
    req.send(postData);
}

var XMLHttpFactories = [
	    function() { return new XMLHttpRequest() },
	    function() { return new ActiveXObject("Msxml2.XMLHTTP") },
	    function() { return new ActiveXObject("Msxml3.XMLHTTP") },
	    function() { return new ActiveXObject("Microsoft.XMLHTTP") }
    ];

function createXMLHTTPObject() {
    var xmlhttp = false;
    for (var i = 0; i < XMLHttpFactories.length; i++) {
        try {
            xmlhttp = XMLHttpFactories[i]();
        }
        catch (e) {
            continue;
        }
        break;
    }
    return xmlhttp;
}