使用javascript做时间倒数读秒功能的实例

<a class="btn btn-default" onclick="StartExamine();">开始</a> <div id="TimeClock" class="col-md-4" ><span class="text-danger hour">00</span> <span class="text-danger minute">00</span> <span class="text-danger seconds">00</span></div>

 var gEaminePapeId = 'dfdfad33434342';    var gExaminePapeTime = '100';        var gHour = gExaminePapeTime / 60;        var gMinute = gExaminePapeTime % 60;     var gSeconds = gExaminePapeTime * 60;    var hour_elem = $("#TimeClock").find('.hour');    var minute_elem = $("#TimeClock").find('.minute');    var second_elem = $("#TimeClock").find('.seconds');    function StartExamine() {       //开始计时            var timeClik = setInterval('ShowClock()', 1000);   }   function ShowClock() {         if (gSeconds > 1) {       gSeconds -= 1;       var hour = Math.floor((gSeconds / 3600) % 24);       var minute = Math.floor((gSeconds / 60) % 60);       var second = Math.floor(gSeconds % 60);       $(hour_elem).text(hour < 10 ? "0" + hour+":" : hour+":"); //计算小时       $(minute_elem).text(minute < 10 ? "0" + minute+":" : minute+":"); //计算分钟       $(second_elem).text(second < 10 ? "0" + second : second); //计算秒杀     }     else {       clearInterval(timeClik);       //做题时间到        ForceSubmit();     }   }       function ForceSubmit() {      //强制提交答题  }