Table with row groups

gistfile1.html

<table class="tablesorter">             
    <thead> 
        <tr> 
            <th>name</th>
        </tr> 
    </thead> 
    <tbody>

        <!-- group 1 -->
        <tr class="top"> 
            <td>Andrew</td>
        </tr>
        <tr class="bottom"> 
            <td></td>
        </tr>

        <!-- group 2 -->
        <tr class="top"> 
            <td>Bob</td>
        </tr>
        <tr class="bottom"> 
            <td></td>
        </tr>

    </tbody>
</table>