JS倒计时 代码

<div>     <span id="KSD">3</span>天     <span id="KSH">12</span>小时     <span id="KSM">39</span>分钟     <span id="KSS">25</span>秒 </div>     <script type="text/javascript"> function countDown(targetTime, callback) {     var t_timestamp = Date.parse(targetTime);     var s_timestamp = new Date();     c_timestamp = t_timestamp - s_timestamp; // 倒计时间戳     if (c_timestamp > 0) {         setTimeout(function callee() {             countdownTime(c_timestamp);             if (c_timestamp > 0) {                 c_timestamp -= 1000;                 setTimeout(callee, 1000);             }         }, 1);     }       // 计算倒计时间(天，小时，分钟，秒)，并传入回调函数，执行回调     function countdownTime(c_timestamp) {         var d, h, m, s;         c_timestamp = c_timestamp / 1000;           d = parseInt(c_timestamp / 3600 / 24, 10); // 天数         h = parseInt(c_timestamp / 3600 % 24, 10); // 小时         m = parseInt(c_timestamp % 3600 / 60, 10); // 分钟         s = parseInt(c_timestamp % 3600 % 60, 10); // 秒           if (typeof callback === 'function') {             callback(d, h, m, s);         }     } };   var targetTime = '2013/11/12 00:00:00'; // 大于本地时间(假如本地时间为：2013/3/14 16:10:00) countDown(targetTime, function(d, h, m, s) {       // 补零     for (var i = 0, len = arguments.length; i < len; i++) {         if (String(arguments[i]).length < 2) {             arguments[i] = '0' + arguments[i];         }     }     // dom操作     document.getElementById('KSD').innerHTML = d;     document.getElementById('KSH').innerHTML = h;     document.getElementById('KSM').innerHTML = m;     document.getElementById('KSS').innerHTML = s; }); </script>