다음과 같은 에러가 발생합니다.

Notice: Use of undefined constant header - assumed 'header' in /home/vivid-viewpoint/bbs/admin/admin_add_group.php on line 36 Notice: Undefined variable: data in /home/vivid-viewpoint/bbs/admin/admin_add_group.php on line 36

Notice: Use of undefined constant footer - assumed 'footer' in /home/vivid-viewpoint/bbs/admin/admin_add_group.php on line 50 Notice: Undefined variable: data in /home/vivid-viewpoint/bbs/admin/admin_add_group.php on line 50

해당라인은

tr height=25 bgcolor=#e0e0e0>
  <td  align=right  style=font-family:Tahoma;font-size:8pt;><b>게시판 상단에 출력될 내용&nbsp;</td>
  <td >&nbsp;&nbsp;
    <textarea name=header cols=70 rows=10 class=textarea style=border-color:b0b0b0><?echo stripslashes($data['header']);?></textarea>    <<<이곳
  </td>
</tr>


그리고

<tr height=25 bgcolor=#e0e0e0>
  <td  align=right style=font-family:Tahoma;font-size:8pt;><b>게시판 하단에 출력될 내용&nbsp;</td>
  <td >&nbsp;&nbsp;
    <textarea name=footer cols=70 rows=10 class=textarea style=border-color:#b0b0b0><?echo stripslashes($data['footer']);?></textarea>  <<<< 이곳입니다.
  </td>
</tr>


어느부분을 손봐야 하는지요..?
답변해주시면 정말 감사하겠습니다ㅜㅜ