function xml_http_call_url(f_url,get_var,on_success,on_fail) {
    var ajax = doXHR( f_url+get_var,{'headers': {'Accept': 'application/javascript'}})

    ajax.addCallbacks(
        function(t){
            var obj = evalJSONRequest(t);

            if (obj.status == 200) {
                if (on_success)
                    on_success(obj.content)
                return;

                } else {
                if (obj.debug) {
                    if (!debug_win || debug_win.closed) {
                        debug_win = window.open("","debug","scrollbars,width=1024,height=800");
                    } else {
                        debug_win.focus();
                    }
                    debug_win.document.write(obj.debug_msg);
                    debug_win.document.close();

                } else {
                    alert("Oops! Error happend while execute XML request. Server return "+obj.status+" code");
                }
            }
            if (on_fail) {
                on_fail(obj.status)
            }
        },
        function(t){
    
            alert("Timeout while XML Http request to server");
            if (on_fail) {
                on_fail(0)
            }
        }
    );
}

function xml_http_call(f_name,get_var,on_success,on_fail) {
    return xml_http_call_url('/xmlhttp/'+f_name+'/',get_var,on_success,on_fail);
}