不知道哪错了，就是运行不出来

window.onload=function(){

var aLi=document.getElementsByTagName('li');

for(var i=0;i<aLi.length;i++){

aLi[i].timer=null;

aLi[i].onmouseover=function(){

startMove(this,400);

}

aLi[i].onmouseout=function(){

startMove(this,200);

}

}

function startMove(obj,iTarget){

clearInterval(obj.timer);

obj.timer=setInterval(function()

{

var speed=(iTarget-obj.offsetWidth)/8;

speed=speed>0?Math.ceil(speed):Math.floor(speed);

if(obj.offsetWidth==iTarget)

{

clearInterval(obj.timer);

}

else{

obj.style.Width=obj.offsetWidth+speed+'px';

}

},10)

}