有一个表,宽度为100%,共有3列,确定第一列与第三列的宽度均为12px,如何根据表的总宽度为100%的情况下, 确定第二列的宽度.<table style="width: 100%; height: 150px">
        <tr>
            <td>
                </td>
            <td>
                </td>
            <td>
               </td>
        </tr>
        <tr>
            <td>
               </td>
            <td>
               </td>
            <td>
                </td>
        </tr>
        <tr>
            <td>
                </td>
            <td>
                </td>
            <td>
                </td>
        </tr>
</table>