javascript实现的仿腾讯QQ窗口抖动效果代码

<img id="win" style='position:relative' src=http://tech.ddvip.com/2008-12/"http://www.jb51.net/upload/20080907101743898.jpg">
<button onclick="zd()">振动</button>
<script >
function zd(u){
var a=['top','left'],b=0;
u=xywInterval(function(){
document.getElementById('win').style[a[b%2]]=(b++)%4<2?0:4;
if(b>15){clearInterval(u);b=0}
},32)
}
</script>
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