style='width:2px;height:20px;background:black'>&nbsp;</div></td>
            <td><div id='left_bottom_a' style='width:4px;height:20px;background:white'>&nbsp;</div></td>
            <td><div id='bottom_a' style='width:10px;height:20px;background:white'>&nbsp;</div></td>
            <td><div id='right_bottom_a' style='width:4px;height:20px;background:white'>&nbsp;</div></td>
            <td><div id='a_b_sep' style='width:2px;height:20px;background:black'>&nbsp;</div></td>
            <td><div id='left_bottom