<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
<style>
*{padding:0; margin:0;}
ul{ list-style:none;}
#div{ width:300px; height:100px; margin:100px auto; border:1px solid #ff0000; position:relative; overflow:hidden;}
#div ul{ position:absolute; height:100px; left:0;}
#div ul li{ width:300px; height:100px; line-height:100px; text-align:center; float:left}
</style>
<script>
window.onload=function(){
var oDiv=document.getElementById("div");
var oUl=oDiv.getElementsByTagName("ul")[0];
var oLi=oUl.getElementsByTagName("li");
var oInput=document.getElementsByTagName('input');
oUl.innerHTML +=oUl.innerHTML;
oUl.style.width=oLi[0].offsetWidth*oLi.length+"px";
var iSeep=-2;
var tamer=null;
clearInterval(tamer);
function starMove(){
tamer=setInterval(function(){
oUl.style.left=oUl.offsetLeft+iSeep+"px";
if(-oUl.offsetLeft >= oUl.offsetWidth/2){
oUl.style.left="0px";
}else if(oUl.offsetLeft>0){
oUl.style.left=-oUl.offsetWidth/2+"px";
}
},30)
}
starMove();
oDiv.onmouseover=function(){
clearInterval(tamer);
}
oDiv.onmouseout=function(){
starMove();
}
oInput[0].onclick=function(){
iSeep=-2;
}
oInput[1].onclick=function(){
iSeep=2;
}
}
</script>
</head>
<body>
<input type="button" value="左">
<input type="button" value="右">
<div id='div'>
<ul>
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
</ul>
</div>
</body>
</html>