JavaScript实现键盘控制的简单抽奖程序

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>简单抽奖（可用键盘）</title>
  <style>
    *{margin:0;padding:0;}
    .box{width: 400px;height: 300px;margin:50px auto;background: red}
    .title{color: #fff;font-size: 30px;font-weight:700px;padding: 50px 0;text-align: center;height:40px;}
    .btm{text-align: center;padding:20px 0;}
    .btm a{display: inline-block;width: 120px;height:60px;line-height: 60px;background: #FEF097;margin:0 10px;text-decoration: none;}
  </style>
  <script>
    var data=['Iphone','Ipad','笔记本','相机','谢谢参与','充值卡','购物券'],
      timer=null,//定时器
      flag=0;//阻止多次回车
    window.onload=function(){
      var play=document.getElementById('play'),
        stop=document.getElementById('stop');
      // 开始抽奖
      play.onclick=playFun;
      stop.onclick=stopFun;
      // 键盘事件
      document.onkeyup=function(event){
        event = event || window.event;
        // 回车键的code值：13
        if(event.keyCode==13){
          if(flag==0){
            playFun();
            flag=1;
           }else{
              stopFun();
              flag=0;
           }
         }
        }
        function playFun(){
        var title=document.getElementById('title');
        var play=document.getElementById('play');
        clearInterval(timer);
        timer=setInterval(function(){
          var random=Math.floor(Math.random()*data.length);
          title.innerHTML=data[random];
        },60);
        play.style.background='#999';
      }
      function stopFun(){
        clearInterval(timer);
        var play=document.getElementById('play');
        play.style.background='#FEF097';
      }
    }
  </script>
</head>
<body>
  <div class="box">
    <div class="title" id="title">淘家趣抽奖</div>
    <div class="btm">
      <a href="javascript:;" id="play">开始</a>
      <a href="javascript:;" id="stop">停止</a>
    </div>
  </div>
</body>
</html>