function CAjax(url, callback) {
    var req = init();
    this.sCont = undefined;
    req.onreadystatechange = processRequest;
    function init() {
        if (window.XMLHttpRequest) {
            return new XMLHttpRequest();
        } else if (window.ActiveXObject) {
            return new ActiveXObject("Microsoft.XMLHTTP");
        }
    }
    function processRequest() {
        if (req.readyState == 4) {
            if (req.status == 200) {
                var ibeg=req.responseText.indexOf('<!-- AJAX-START -->');
                var iend=req.responseText.indexOf('<!-- AJAX-END -->');
                this.sCont=req.responseText.substring((ibeg+19),iend);
                if (callback) callback(this.sCont);
            }
        }
    }
    this.doGet = function() {
        req.open("GET", url, true);
        req.send(null);
    }
    this.doPost = function(body) {
        req.open("POST", url, true);
        req.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
        req.send(body);
    }
    this.doGet();
}