定时器清除不了
倒数到0的时候还在后台倒计时，根本停不下来，这样浏览器很容易崩溃吧，分别试了setTimeout和setInterval，定时器写里面外面都清不掉，是我写错了吗？望大神小神过来搭救~
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>团购——限时抢</title>
<!-- <link rel="stylesheet" href="style.css" /> -->
</head>
<body>
<div class="content3">
<div class="time">还剩 <span id="LeftTime"></span></div>
</div>
<script>
window.onload=function(){
FreshTime()
// var sh;
// sh=setInterval(FreshTime,500);
// sh=setTimeout(FreshTime,500); 不能写函数外面，只调用一次！！
}
function FreshTime()
{
var endtime=new Date("2017/1/7,10:31:40");//结束时间
var nowtime = new Date();//当前时间
var lefttime =parseInt((endtime.getTime() - nowtime.getTime())/1000);
var d = parseInt(lefttime/(24*60*60)); //把总共的秒数除以一天的秒数
var h = parseInt(lefttime/(60*60)%24); //取模得出当前剩下的小时数
var m = parseInt(lefttime/60%60);
var s = parseInt(lefttime%60);
document.getElementById("LeftTime").innerHTML=d+"天"+h+"小时"+m+"分"+s+"秒";
if(lefttime<=0){
document.getElementById("LeftTime").innerHTML="团购已结束";
// clearTimeout(sh);
clearInterval(sh);
}
// sh=setTimeout(FreshTime,500);
sh=setInterval(FreshTime,500);
console.log(d+"天"+h+"小时"+m+"分"+s+"秒"); //注意控制台的变化
}
</script>
</body>
</html>
