js倒计时天时分秒[转]

<script language="JavaScript">
<!--  //

function getQueryString(name) {
var reg =new RegExp("(^|&)"+ name +"=([^&]*)(&|$)", "i");
var r = window.location.search.substr(1).match(reg);
if (r !=null) return unescape(r[2]); return null;
}

var currentDate = new Date();
var strEndTime = getQueryString("EndTime");//http://www.abc.com/page.html?EndTime=2012/10/23 10:20:30
var EndTime=new Date(strEndTime);

var days= EndTime - currentDate;
EndTimeMsg = parseInt(days / 1000);//精确到秒

function show() {
h = Math.floor(EndTimeMsg / 60 / 60);
m = Math.floor((EndTimeMsg - h * 60 * 60) / 60);
s = Math.floor((EndTimeMsg - h * 60 * 60 - m * 60));
document.getElementById("DD").innerHTML = parseInt(h/24);
document.getElementById("HH").innerHTML = h;
document.getElementById("MM").innerHTML = m;
document.getElementById("SS").innerHTML = s;
EndTimeMsg--;
if (EndTimeMsg < 0)
{
document.getElementById("DD").innerHTML = "0";
document.getElementById("HH").innerHTML = "00";
document.getElementById("MM").innerHTML = "00";
document.getElementById("SS").innerHTML = "00";;
}
}
setInterval("show()", 1000)

// -->
</script>

<div>
<strong id="DD"></strong>天 <strong id="HH"></strong>时 <strong id="MM"></strong>分 <strong id="SS"></strong>秒
</div>