ecco

codice:
<table border="1" width="100%" style="border-left: 1 solid #000000; border-right: 1 solid #00FF00; border-top: 1 solid #00FF00; border-bottom: 1 solid #000000">
  <tr>
    <td width="50%"></td>
    <td width="50%"></td>
  </tr>
</table>