while($data = mysql_fetch_assoc($sql2))
{
    $images[] = $data['location'];
}
?>

              </tr>
                          <tr>
                                        <td colspan="5"><p align="center"><img src="<?php echo $images[0]?>"/> 
                        </p></td> </tr> 
 
                                        <tr>
 
                                        <td><p align="center"><img src="<?php if(!isset($images) ||empty($images)){ echo $images[1]; } ?>" width="100" height="40" /></td>
										 <td><p align="center"><img src="<?php  if(!isset($images) ||empty($images)){ echo $images[2]; }?>" width="100" height="40" /> </td>
                                        <td><p align="center"><img src="<?php  if(!isset($images) ||empty($images)){ echo $images[3];  } ?>" width="100" height="40"/> <?php var_dump(isset($images)); ?></td>
                                       </tr>