function AjaxGetData(url, responseHandler) {
    if (window.XMLHttpRequest) {
        // browser has native support for XMLHttpRequest object
        req = new XMLHttpRequest();
    }
    else if (window.ActiveXObject) {
        // try XMLHTTP ActiveX (Internet Explorer) version
        req = new ActiveXObject("Microsoft.XMLHTTP");
    }

    if (req) {
        req.onreadystatechange = responseHandler;
        //alert(url);
        req.open('GET', url, true);
        req.setRequestHeader("content-type", "application/x-www-form-urlencoded");
        req.send('');
    }
    else {
        alert('Your browser does not seem to support XMLHttpRequest.');
    }
}

function GmapsHandler() {

    try {
        //readyState of 4 or 'complete' represents
        //that data has been returned
        if (req.readyState == 4 ||
            req.readyState == 'complete') {
            var res = req.responseText;
            var xml = GXml.parse(res);
            var markers = xml.documentElement.getElementsByTagName("marker");
            for (var i = 0; i < markers.length; i++) {
                point = new GLatLng(parseFloat(markers[i].getAttribute("lat")),
                            parseFloat(markers[i].getAttribute("lng")));
                var infoHtml = markers[i].getAttribute("infoHtml");

                marker = new GMarker(point);
                GEvent.addListener(marker, 'click', function() {
                    marker.openInfoWindowHtml(infoHtml);
                });
                map.addOverlay(marker);
            }
        }
    }
    catch (e) {
        alert('Error in Ajax respone');
    }
}