秒杀的倒计时按钮实现

ps：只有按钮没有秒杀还在做
一个小小的按钮花了我一个下午的时间  自己水平还是太次啊
直接贴代码html>
html lang="en">
head>
meta charset="UTF-8">
</title>
script>
head>
body>

br>

input type="button" id="btn" value="秒杀" disabled="true"/>
body>
script type="text/javascript">
$(function(){
var stringTime = "2017-04-27 19:44:00";
var timestamp2 = Date.parse(new Date(stringTime));
timestamp2 = timestamp2 / 1000;  //获取到的格式日期的时间戳

var myDate = new Date();
var timestamp = myDate.getTime()/1000;  //当前时间戳获取的时间戳为毫秒需除1000
timestamp = timestamp.toFixed();

//过了某时间直接不可点
var stringTime3 = "2017-04-27 20:02:00";
var timestamp4 = Date.parse(new Date(stringTime3));
timestamp4 = timestamp4 / 1000;  //获取到的格式日期的时间戳
if(timestamp>timestamp4){
      alert('活动已结束');
      return;
}

if(timestamp>timestamp2 && timestamp<timestamp4){
      $("#btn").val("秒杀").removeAttr("disabled");
      return;
}

var count = timestamp2 - timestamp;

var countdown = setInterval(CountDown, 1000);
function CountDown() {
      $("#btn").val("离活动开始还有" + count + "秒");
      if (count == 0) {
         $("#btn").val("秒杀").removeAttr("disabled");
         clearInterval(countdown);
      }
      count--;
}
});
script>
http://www.cnblogs.com/zyjfire/articles/6775383.html  食用