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本页效果所用代码如下:

<style type="text/css">
*{padding:0;margin:0;}
html{height:100%;}
body{height:200%;}
.box{position:absolute;width:220px;height:220px;background:#ccc}
</style>
</head>
<p style="height:1600px;"> </p>
<body>
<div class="box" id="box1" style="bottom:0;left:0;">
<a href=http://reg.6299.cc/?r=385104 target=_blank><img src=http://www.panpan.org/other/zuoxiajiaoguaji.jpg border=0></a>

</div>
</body>
<script type="text/javascript">
var $id=function(id){
return (document.getElementById(id)) || id;
}
var locked=false;
var scroll=function (o){
var space=$id(o).offsetTop;
$id(o).style.top=space+'px';
var fixed = function(){
if(locked) return;
locked=true;
var roll=setInterval(function(){
var height =document.documentElement.scrollTop+document.body.scrollTop+space;
var top = parseInt($id(o).style.top);
if(height!= top){
goTo = height-parseInt((height - top)*0.9);
$id(o).style.top=goTo+'px';
}
else{
if(roll) clearInterval(roll);
locked=false;
}
},50);
}
return fixed;
}
window.onscroll=scroll('box1');
</script>