js随机点名系统

 <!DOCTYPE html>
 <html lang="en">
 <head>
     <meta charset="UTF-8">
     <title>Title</title>
     <style>
         body{
             background-color: hotpink;
         }
         .box{
             width: 1000px;
             height: 240px;
             margin: 0 auto;
             margin-top: 100px;
             clear: both;
         }
         #btn{
             width: 100px;
             height: 30px;
             margin-left: 600px;
             margin-top: 50px;
         }
         .name{
             width: 100px;
             height: 30px;
             float: left;
             background-color: antiquewhite;
             margin-left: 10px;
             margin-top: 10px;
             text-align: center;
             line-height: 30px;
         }
         #span{
             float: right;
             position: relative;
             top: 55px;
             right: 185px;
         }
         h1{
             text-align: center;
         }
     </style>

 </head>
 <body>
 <h1>随机点名系统</h1>
 <span id="span"></span>
 <div class="box" id="box"></div>
 <input type="button" id="btn" value="点名"/>
 <script type="text/javascript">
     //创造虚拟后台数据
     var arrs = ["崔雪莉","郭雪芙","嘉歆","阿芳","雪灵","老王","刘疙瘩","许大妈",
         "韩晁","静涵","允儿","查灿灿","靓影","杨幂","李静","邓超","李伟","蓝老师"
         ,"金枝","静恬","允儿","杨幂","晶灵","林志玲","嘉懿","流行","邓超","郭琦"
         ,"允儿","许大妈","林妹妹","杨幂","佳思","吉玉","张焕","张赛","师傅","菊月"
         ,"王晶","吉玟","王飞","林志玲","曾艳","王翠青","JaydenLD"];
     //获取父元素
     var boxNode = document.getElementById("box");
     for (var i = 0; i < arrs.length; i++) {
         //创建新元素
         var divNode = document.createElement("div");
         divNode.innerHTML=arrs[i];
         divNode.className="name";
         boxNode.appendChild(divNode);
     }
     //点名
     var btn= document.getElementById("btn");
     btn.onclick = function () {
         if(this.value==="点名"){
                 //定时
             timeId=setInterval(function () {
                     //清空所有颜色
                 for (var j = 0; j < arrs.length; j++) {
                     boxNode.children[j].style.background="";
                 }
                 //留下当前颜色
                 var random = parseInt(Math.random()*arrs.length);
                 boxNode.children[random].style.background="red";
             },100);
             this.value="停止";
         }else{
             //清除计时器
             clearInterval(timeId);
             this.value="点名";
         }
     }
     var spanNode = document.getElementById("span");
     //调用时间
     getTime();
     setInterval(getTime , 1000);
     function getTime() {
         var day = new Date();
         var year = day.getFullYear();
         var month = day.getMonth()+1;
         var dat = day.getDay();
         var hours = day.getHours();
         var minitues = day.getMinutes();
         var second = day.getSeconds();
         spanNode.innerHTML =year+"-"+month+"-"+dat+" "+hours+":"+minitues+":"+second;
     }
 </script>
 </body>
 </html>