如何给datalist设定滚动时间

怎么给datalist设定滚动时间
function top() {
        var speed = 40;//设置滚动速度
        demo2.innerHTML = demo1.innerHTML//复制demo1为demo2

        function Marquee() {
            if (demo1.offsetWidth - demo.scrollLeft <= 0)//当滚动至demo1与demo2交界时
                demo.scrollTop = 0  //demo跳到最左端
            else
                demo.scrollTop++
        }
}

求教！ JS
[解决办法]
里面加个定时器，setTim

<div id="colee" style="overflow:hidden;height:253px;width:410px;">

<div id="colee1">

<p><img src="/jscss/demoimg/200907/bg3.jpg"></p>

<p><img src="/jscss/demoimg/200907/bg3.jpg"></p>

<p><img src="/jscss/demoimg/200907/bg3.jpg"></p>

<p><img src="/jscss/demoimg/200907/bg3.jpg"></p>

<p><img src="/jscss/demoimg/200907/bg3.jpg"></p>

<p><img src="/jscss/demoimg/200907/bg3.jpg"></p>

</div>

<div id="colee2"></div>

</div>

<script>

var speed=30;

var colee2=document.getElementById("colee2");

var colee1=document.getElementById("colee1");

var colee=document.getElementById("colee");

colee2.innerHTML=colee1.innerHTML; //克隆colee1为colee2

function Marquee1(){

//当滚动至colee1与colee2交界时

if(colee2.offsetTop-colee.scrollTop<=0){

 colee.scrollTop-=colee1.offsetHeight; //colee跳到最顶端

 }else{

 colee.scrollTop++

}

}

var MyMar1=setInterval(Marquee1,speed)//设置定时器

//鼠标移上时清除定时器达到滚动停止的目的

colee.onmouseover=function() {clearInterval(MyMar1)} 
 

//鼠标移开时重设定时器

colee.onmouseout=function(){MyMar1=setInterval(Marquee1,speed)}

</script>