var RqSendDataAjx = null;
            function goSayPresence()
            {
                try
                {
                    RqSendDataAjx = goCmdAjax(null, 'GET', '/PageAlive/SayPresence/', null, null);
                }
                catch (e)
                {
                    //timerSayAlive();
                }
                CheckError();
            }; 
            


            var onTimer = false;
            var goTimer = false;
            var timerSend = null;


            function CheckReTimer()
            {
                if (goTimer && !onTimer)
                {
                    onTimer = true;
                    goTimer = false;
                    clearInterval(timerSend);
                    timerSend = setTimeout("goSayPresence(); onTimer = false; ", 20000);
                }
            };

            setInterval("CheckReTimer()", 500);



            function CheckError()
            {
                if (RqSendDataAjx.readyState != 4) 
                {
                    setTimeout("CheckError()", 200);
                    return;
                }

                if (RqSendDataAjx.status == 200 || RqSendDataAjx.status == 201 || RqSendDataAjx.status == 500) 
                    timerSayAlive();

                
            };


            function timerSayAlive()
            {
                goTimer = true;
            };         

            timerSayAlive();