Timer concept javascript asp.net

In this example we have shown SetInveral   JavaScript function how to use. The following example is give below

  <span id="sptimeLeft" style="font-weight: bold; color: red"></span>

<script type="text/javascript">

             var tm = null;

                function TimerDisplay(n) {

                    tm = setInterval(countDown, 1000);

                    function countDown() {

                        n--;

                        if (n == 0) {

                            clearInterval(tm);

                        }

                        $("#sptimeLeft").html(n + " seconds Left");

                    }

                }

        $(function () {

            $(".red").on('click', function () {

               

                    TimerDisplay40);

               

                else {

                    clearInterval(tm);

                    $("#sptimeLeft").html("");

                }

            }

            );

        });

    </script>