JS抽奖功能代码

<label for="awardListDom">奖项列表</label><br>
<input type="text" value="" id="awardListDom"> <br>
<label for="num">抽到的奖</label><br>
<input type="text" value="" id="num"> <br>
<button id="submit">开始抽奖</button>

<script>
  function random(min,max){
    return Math.floor(min+Math.random()*(max-min));
  }
  var awardListDom=document.getElementById("awardListDom"),
  num=document.getElementById("num"),
  submit=document.getElementById("submit");
  var awardList=["一等奖","二等奖","二等奖","三等奖","三等奖","三等奖","鼓励奖","鼓励奖","鼓励奖","鼓励奖","谢谢参与","谢谢参与","谢谢参与","谢谢参与","谢谢参与","谢谢参与"];

  awardListDom.value=awardList;
  submit.onclick=function(){
   //引用数组
   var oldArray=awardList;
   var rNum=random(0,oldArray.length);
   
   if(oldArray.length<1){
    awardListDom.value="活动结束";
    num.value="活动结束";
   }
   else{
    num.value=oldArray[rNum];
    oldArray.splice(rNum,1);
    awardListDom.value=oldArray;
   }
  }
</script>