在购物网站中经常会见到倒计时的功能，这里简单做个demo，是从数据库中取得团购的结束时间，主要代码如下：

<script type="text/javascript">
        function fresh() {
            var d = "<%=G_DATE %>";
            var endtime = new Date(d);
            var nowtime = new Date();
            var leftsecond = parseInt((endtime.getTime() - nowtime.getTime()) / 1000);
            d = parseInt(leftsecond / 3600 / 24);
            h = parseInt((leftsecond / 3600) % 24);
            m = parseInt((leftsecond / 60) % 60);
            s = parseInt(leftsecond % 60);
            var msg = "还剩余"+d+"天"+h+“小时”+m+"分"+s+“秒！”;
            if (leftsecond <= 0) {
                $("#clock").html("团购已结束！");
                clearInterval(sh);
            }
        }
        fresh();
        var sh;
        sh = setInterval(fresh, 1000);  
    </script>

<div id="clock">
           
 </div>

public string G_DATE = "";
public void Page_Load(object sender,EventArgs e)
{
       if(!IsPostBack)
      {
            //从数据库表中获取对应的结束时间
            G_DATE = "2013/10/01 18:18:00";
      }
}