js实现倒计时
<html><head><title>倒计时</title><!--以下为css样式--><style type= "text/css">.daojishi h2{ font-family:Helvetica, Microsoft YaHei, Arial, sans-serif; font-size:14px;margin-bottom:5px; color:#151515;}.daojishi #timer{font-family:Helvetica, Microsoft YaHei, Arial, sans-serif; font-size:14px;color:#151515;font-weight:bold;}</style><script type = "text/javascript" src = "timer.js"></script></head><body onload = "timer()"><div class = "daojishi"><h2>剩余时间为：</h2><div id = "timer"></div></div></body></html>
timer.js
function timer(){var ts = (new Date(2012, 11, 11, 9, 0, 0)) - (new Date());//计算剩余的毫秒数var dd = parseInt(ts / 1000 / 60 / 60 / 24, 10);//计算剩余的天数var hh = parseInt(ts / 1000 / 60 / 60 % 24, 10);//计算剩余的小时数var mm = parseInt(ts / 1000 / 60 % 60, 10);//计算剩余的分钟数var ss = parseInt(ts / 1000 % 60, 10);//计算剩余的秒数dd = checkTime(dd);hh = checkTime(hh);mm = checkTime(mm);ss = checkTime(ss);document.getElementById("timer").innerHTML = dd + "天" + hh + "时" + mm + "分" + ss + "秒";setInterval("timer()",1000);}function checkTime(i) { if (i < 10) { i = "0" + i; } return i; }