JS实现兼容性好、自动置顶的淘宝悬浮工具栏效果

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<html xmlns="http://www.w3.org/1999/xhtml"> 
<head> 
<title>兼容IE6的淘宝悬浮工具栏</title> 
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
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<div style="height:300px;background:#eee"></div> 
<div id="box"><div id="float" ></div></div> 
<div style="height:1000px;background:#eee"></div> 
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