daojishi

<div  id="divdown1"> </div>                                 
         <script language="javascript" type="text/javascript">
var interval = 1000;
var timeCount=15;
window.setInterval(function(){timeCountdown("divdown1");},1000);
function timeCountdown(divname){
var cc = document.getElementById(divname);
if(timeCount>0){
timeCount=timeCount-1;
}
cc.innerHTML ="还有  "+timeCount+" 秒";
return timeCount;
}
</script>