<body onscroll="setTop();">
<script language="javascript">
function setTop()
{
adLeft.style.posTop = document.body.scrollTop + 300;
adRight.style.posTop = document.body.scrollTop + 300;
}function closeAd()
{
adLeft.style.display='none';
adRight.style.display='none';
}
</script>
<div id="adLeft" style="width: 50; height: 300; position: absolute; left: 10; top:30;border:1 solid red;text-align:center;padding:6px;"><span style="font-size:12px;color:#336699;cursor:hand;" onclick="closeAd();">关闭</span></div>
<div id="adRight" style="width: 50; height: 300; position: absolute; left: 720; top:30;border:1 solid red;text-align:center;padding:6px;"><span style="font-size:12px;color:#336699;cursor:hand;" onclick="closeAd();">关闭</span></div>
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