时间倒计时：时分秒，累积

 -------还有多少时，分，秒-----------
var dateTmpStart=  new Date().getTime();
        var exam_now = new Date(dateTmpStart);
       
        function getServerTime()
        {
            var dateTmpEnd=GetCookie('ckTimeEnd');
            dateTmpEnd=dateTmpEnd.replace('+',' ');
         var urodz    = new Date(dateTmpEnd);
         var time_str = "";
         var time_str_pre = "距本次考试结束还剩:";

         exam_now.setTime(exam_now.getTime()+1000);
         time_phase = urodz - exam_now;

         if ( time_phase<=0 )
         {
             time_str  = time_str_pre + "0秒";
          need_get  = 0;
          clearInterval(check_time);   //卸载setInterval
         }
         else
         {
          hours        = (urodz - exam_now) / 1000 / 60 / 60;
          hoursRound   = Math.floor(hours);
          minutes      = (urodz - exam_now) / 1000 /60 - (60 * hoursRound);
          minutesRound = Math.floor(minutes);
          seconds      = (urodz - exam_now) / 1000 - (60 * 60 * hoursRound) - (60 * minutesRound);
          secondsRound = Math.round(seconds);
          if( hoursRound !=0 )
          {
           time_str = time_str_pre + hoursRound   + "时" + minutesRound + "分" + secondsRound + "秒";
          }
          else if ( minutesRound!=0 )
          {
           time_str = time_str_pre + minutesRound + "分" + secondsRound + "秒";
          }
          else
          {
           time_str = time_str_pre + secondsRound + "秒";
          }
         }
         document.getElementById("time").innerHTML = time_str;
        }
-------

          <script language="JavaScript" type="text/javascript">
                check_time = setInterval("getServerTime()",1000);
            </script>
<span id="time" style="color:Red;"></span>

------------时间累计--------------------------------------------------------------
        var i=0;
        var time=0;
        function totalTime()
        {
            document.getElementById("totalTime").innerHTML=time+i;
            i++;
        }
        timer=setInterval('totalTime()',1000);
<span id="totalTime" style="color:Red;"></span>
---------到达一定时间后，跳转到某页--------------------------------------------------

<script language="JavaScript" type="text/jscript">
<!--
var time = 30; //时间,秒
var URL="<%=UrlStr %>";
function Redirect(){
window.location = URL;
}
var i = 0;
function dis(){
document.all.Span1.innerHTML = "还剩 " + (time - i) + " 秒";
i++;
}
timer=setInterval('dis()', 1000);//显示时间
timer=setTimeout('Redirect()',time * 1000); //跳转

//-->
</script>
<span id="Span1" style="color:Red;"></span>