1 <form id="frm" action="http://www.baidu.com">
2 考试还剩余<div id="time"></div>
3 </form>
4 <script>
5 var times = 45 * 60;//剩余时间,单位秒
6 var timeDiv = document.getElementById("time");
7 var timeObj = null;
8 function timer(){
9 if(times == 0){
10 //倒计时结束，提交表单
11 document.getElementById("frm").submit();
12 window.clearInterval(timeObj);
13 return;
14 }
15 var t = Math.floor(times/60) +"分"+times%60+"秒"
16 timeDiv.innerHTML = t;
17 times --;
18 }
19 timeObj = window.setInterval(timer,1000);
20 </script>
