滑动问题，找不出问题了，谁帮忙看下
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>777666</title>
<style>
*{margin:0;padding: 0;}
li{
width: 200px;
height: 100px;
background: #834;
margin-bottom: 15px;
list-style: none;
}
</style>
<script>
window.onload=function(){
var ali = document.getElementsByName('li');
for(var i=0;i<ali.length;i++){
ali[i].onmouseover=function(){
moves(this,400);
}
ali[i].onmouseout=function(){
moves(this,200);
}
}
}
var mytime;
function moves(obj,tar){
clearInterval(mytime);
mytime=setInterval(function(){
var speed=(tar-obj.offsetWidth)/10;
speed=speed>0?Math.ceil(speed):Math.floor(speed);
if(obj.offsetWidth==tar){
clearInterval(mytime);
}else{
obj.style.width=obj.offsetWidth+speed+'px';
}
},30)
}
</script>
</head>
<body>
<ul>
<li></li>
<li></li>
<li></li>
<li></li>
</ul>
</body>
</html>
