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);
}
}
}
// var timer = null;
function startMove(obj,iTarget){
clearInterval(obj.timer);
obj.timer = setInterval(function(){
var speed = (iTarget-obj.offsetWidth)/10;
speed = speed>0?Math.ceil(speed):Math.floor(speed);
if(obj.offsetWidth == iTarget){
clearInterval(obj.timer);
}
else{
obj.style.width=obj.offsetWidth+speed+'px';
}
},30)
}