相关疑难解决方法(0)

我有以下表结构:

<table>   
<thead>   
    <tr>   
        <th colspan="4">Current</th>   
        <th colspan="4">New/Requested</th>   
    </tr>   
    <tr>   
        <th nowrap="nowrap">RSD &nbsp;&nbsp;&nbsp;&nbsp;</th>  
        <th nowrap="nowrap">CRSD &nbsp;&nbsp;&nbsp;&nbsp;</th>   
        <th nowrap="nowrap">MSD &nbsp;&nbsp;&nbsp;&nbsp;</th>   
        <th nowrap="nowrap">Open QTY &nbsp;&nbsp;&nbsp;&nbsp;</th>   
        <th nowrap="nowrap">CRD &nbsp;&nbsp;&nbsp;&nbsp;</th>   
        <th nowrap="nowrap">CRSD &nbsp;&nbsp;&nbsp;&nbsp;</th>  
        <th nowrap="nowrap">MSD &nbsp;&nbsp;&nbsp;&nbsp;</th>   
        <th nowrap="nowrap">Open QTY &nbsp;&nbsp;&nbsp;&nbsp;</th>   
        <th nowrap="nowrap">Action</th>   
        <th nowrap="nowrap">Reason</th>   
        <th nowrap="nowrap">Action Code Status </th>   
    </tr> 
    <tbody>
        <tr>
            <td></td>  
            <td></td>   
            .....plenty of rows
        </tr>
    </tbody>
</thead>   
</table> 

我正在尝试修复标题,以便如果我向下滚动它仍然可见.我查看了这篇文章,但无法理解.我怎样才能做到这一点？