table内的文字上下滚动

<html><head>
<meta http-equiv="content-type" content="text/html; charset=gbk">
<style>
.yellow{
color:#FF0;
}
</style>
</head>
<body>

<table align="center" bgcolor="#cccccc" border="0" cellpadding="0" cellspacing="1" width="381">
<tr>
<td class="yellow" align="center" bgcolor="#000000" height="21" width="47">合约</td>
<td class="yellow" align="center" bgcolor="#000000" height="21" width="47">开盘价</td>
<td class="yellow" align="center" bgcolor="#000000" height="21" width="47">最高价</td>
<td class="yellow" align="center" bgcolor="#000000" height="21" width="48">最低价</td>
<td class="yellow" align="center" bgcolor="#000000" height="21" width="48">最新价</td>
<td class="yellow" align="center" bgcolor="#000000" height="21" width="48">涨跌</td>
<td class="yellow" align="center" bgcolor="#000000" height="21" width="48">成交量</td>
<td class="yellow" align="center" bgcolor="#000000" height="21" width="48">持仓量</td>
</tr>
</table>

<table align="center" bgcolor="#cccccc" border="0" cellpadding="0" cellspacing="0" width="381">
<tr>
<td width="381">
<div >0</td>
</tr>
</table>
</div>
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</div>
<!-- demohq -->
</td>
</tr>
</table>


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var speedhq=60;
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demohq.scrollTop=0;
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var MyMarhq=setInterval(Marqueehq,speedhq)
demohq.onmouseover=function() {clearInterval(MyMarhq)}
demohq.onmouseout=function() {MyMarhq=setInterval(Marqueehq,speedhq)}
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</body>
</html>