<HTML>
<body>
<table id="myTable" border="3" rules="">
<thead>
<tr>
<td>Header</td>
<td>Header</td>
<td>Header</td>
<td>Header</td>
<td>Header</td>
<td>Header</td>
</tr>
</thead>
<tr>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
</tr>
<tr>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
</tr>
<tr>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
</tr>
<tr>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
</tr>
<tfoot>
<tr>
<td>Footer</td>
<td>Footer</td>
<td>Footer</td>
<td>Footer</td>
<td>Footer</td>
<td>Footer</td>
</tr>
</tfoot>
</table>
<br>
<button onclick="myTable.rules="none"">none</button>
<button onclick="myTable.rules="all"">all</button>
<button onclick="myTable.rules="cols"">cols</button>
<button onclick="myTable.rules="groups"">groups</button>
<button onclick="myTable.rules="rows"">rows</button></body>
</HTML>