How to change the style for the row while mouse over the cell of that row?

[Cylix]

I remember that I done this task by simply
<tr onMouseOver="this.className='withBorder'"> .... </tr>

..withBorder {
border-bottom: 1px dashed #000000;
}

I get the result by simply put it in the cell, like:
<td class="withBorder"> ... </td>

Please advise.