jquery 24小时计时器,精确到秒!

最大24小时计时,精确到秒. <table> <tr> <td><span id="hour">00</span>_小时</td> <td><span id="mi">00</span>_分</td> <td><span id="s">00</span>_秒</td> </tr> </table> <input type="button" value="开始(s)" id="begin" />&nbsp; <input type="button" value="暂停(p)" id="pause" />&nbsp; <input type="button" value="清除" id="clear" />