Detecting the idle time. if user is idle state auto execute url

Javascript code to detect the idle state

<script type="text/javascript">
var idleTime = 0;
$(document).ready(function () {
    //Increment the idle time counter every minute.
    var idleInterval = setInterval(timerIncrement, 60000); // 1 minute

    //Zero the idle timer on mouse movement.
    $(this).mousemove(function (e) {
        idleTime = 0;
    });
    $(this).keypress(function (e) {
        idleTime = 0;
    });
});

function timerIncrement() {
    idleTime = idleTime + 1;
    if (idleTime > 19) { // 20 minutes
        window.location.reload();
        //     (or)
        location.href='logout.php';
    }
}
</script>