php ajax auto logout with timer

[khalif62]

\[code\]<script type="text/javascript">var t;function startTimer(){t=setTimeout("document.location='../login/logout.php'", 50000);}function stopTimer(){clearTimeout(t);}</script>\[/code\]This is my script for auto logout, i want to show the countdown timer, How to create and show the timer, Also i want to make alive when the user hit the body of the page, Also timer should reset and then restart again when system is idle, How to make it, (Timer should show , that is , timer should run when people not touching the system , if user touch the system then counter should restart )