function xmlhttpPost(strURL) {
        var xmlHttpReq = false;
        // Mozilla/Safari
        if (window.XMLHttpRequest) {
            xmlHttpReq = new XMLHttpRequest();
            if (xmlHttpReq.overrideMimeType) {
                xmlHttpReq.overrideMimeType('text/xml');
                // See note below about this line
            }
        // IE
        } else if (window.ActiveXObject) { // IE
            try {
                xmlHttpReq = new ActiveXObject("Msxml2.XMLHTTP");
        } catch (e) {
            try {
                xmlHttpReq = new ActiveXObject("Microsoft.XMLHTTP");
            } catch (e) {}
            }
        }
        if (!xmlHttpReq) {
            alert('ERROR AJAX:( Cannot create an XMLHTTP instance');
            return false;
        }   
        xmlHttpReq.open('GET', strURL, true);
        xmlHttpReq.setRequestHeader('Content-Type', 
            'application/x-www-form-urlencoded');        
        xmlHttpReq.onreadystatechange = function() { 
            callBackFunction(xmlHttpReq); 
        };
        xmlHttpReq.send(""); 
    }