随机数

<!DOCTYPE html>
<html>
   <head>
       <meta charset="UTF-8">
       <title></title>
   </head>
   <body>
       <div id="one" style="color:red ;font-size:10cm; text-align:center;">0</div>
       <script>
       one=document.getElement("one")
       var i=1;
       var dt=null;
       function stop(){
           clearInterval(dt)
       }
       function star(){
           dt=setInterval(function(){
               one.innerText=Math.round(Math.random()*100)
           },50)
       }
       </script>
       <button onclick="star()">开始</button>
       <button onclick="stop()">结束</button>

   </body>
</html>