html如何做到图片自动滚动,如何在HTML页面中实现图片循环滚动？

var speed=30//速度数值越大速度越慢

var demo2 = document.getElementById("demo2");

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

var demo1 = document.getElementById("demo1");

demo2.innerHTML=demo1.innerHTML

function Marquee(){

if(demo2.offsetWidth-demo.scrollLeft