function sendReq(url){
    var xmlHttpReq = false;
    var self = this;
    var strURL = url;
    if (window.XMLHttpRequest) { // Mozilla/Safari
        self.xmlHttpReq = new XMLHttpRequest();
    } else if (window.ActiveXObject) { // IE
        self.xmlHttpReq = new ActiveXObject("Microsoft.XMLHTTP");
    }
    self.xmlHttpReq.open('POST', strURL, true);
    self.xmlHttpReq.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    self.xmlHttpReq.onreadystatechange = function() {
        if (self.xmlHttpReq.readyState == 4) {
            updatePage(self.xmlHttpReq.responseText);
        }
    }
     self.xmlHttpReq.send(getQueryString());
}