调试易

<table bgcolor="#000000" cellpadding="1" cellspacing="1">
<tr bgcolor="#FFFFFF"><td>&nbsp;</td></tr>
<tr bgcolor="#FFFFFF"><td>&nbsp;</td></tr>
</table>

<table rules="rows" border="1">
<tr>
<td>ab</td>
<td>c</td>
</tr>
<tr>
<td>d</td>
<td>e</td>
</tr>
</table>
<table rules="cols" border="1">
<tr>
<td>ab</td>
<td>c</td>
</tr>
<tr>
<td>d</td>
<td>e</td>
</tr>
</table>

<style>
.tbl1 {
border-collapse:collapse;
}
.tbl1 td {
    border-top:1px solid black;
border-bottom:1px solid black;
}
.tbl2 {
border-collapse:collapse;
}
.tbl2 td {
    border-left:1px solid black;
border-right:1px solid black;
}
</style>
<input type=button value='只显示水平线' onclick='ice.className="tbl1"'>
<input type=button value='只显示垂直线' onclick='ice.className="tbl2"'>
<p></p>
<table class='tbl1' id='ice'>
<tr>
<td>one</td>
<td>tow</td>
<td>three</td>
<td>four</td>
</tr>
<tr>
<td>one</td>
<td>tow</td>
<td>three</td>
<td>four</td>
</tr>
<tr>
<td>one</td>
<td>tow</td>
<td>three</td>
<td>four</td>
</tr>
<tr>
<td>one</td>
<td>tow</td>
<td>three</td>
<td>four</td>
</tr>
</table>