精确到微秒的倒计时代码

<DIV id=time_conter
style="DISPLAY: none; bgcolor:#ccffff; FONT-WEIGHT: bold; WIDTH: 100%; COLOR: #cc0000; PADDING-TOP: 150px; FONT-FAMILY: arial; TEXT-ALIGN: center;">
 
<P style="font-size:12px;">离国庆节倒计时还有</P>
 
 
<DIV style="FONT-SIZE: 38px"><SPAN id=h></SPAN>小时<SPAN id=m></SPAN>分<SPAN
id=s></SPAN>秒<SPAN id=ms></SPAN>微秒</DIV>
</DIV>
 
 
<SCRIPT language=javascript>
function n2(n)
{
if(n < 10)return "0" + n.toString();
return n.toString();
}
 
function n3(n)
{
if(n < 10)return "00" + n.toString();
if(n < 100)return "0" + n.toString();
return n.toString();
}
 
function setLeft()
{
var d1 = new Date();
var n;
 
n = (d.getTime() - d1.getTime());
document.getElementById("ms").innerHTML = n3(n % 1000);
n = (n - n % 1000) / 1000;
document.getElementById("s").innerHTML = n2(n % 60);
n = (n - n % 60) / 60;
document.getElementById("m").innerHTML = n2(n % 60);
n = (n - n % 60) / 60;
document.getElementById("h").innerHTML = n2(n);
 
setTimeout("setLeft();", 1);
}
 
var a, a1, a2;
a = unescape("2009-10-1 00:00:00").split(" ");
if(a.length > 1)
{
document.getElementById("time_conter").style.display="";
a1 = a[0].split("-");
a2 = a[1].split(":");
 
var d = new Date(a1[0], a1[1] - 1, a1[2], a2[0], a2[1]);
 
setLeft();
}
</SCRIPT>