뭐가 잘못됐는지 알수가 없습니다.

<!-- { 이전글 다음글 -->    <div class="prv_head01 prv_wrap">        <table>        <caption><?php echo $board['bo_subject'] ?> 이전글 다음글 보기</caption>        <thead>        <tr>  <td scope="col" bgcolor=#f4f4f4 style="text-align:center; width:100px;">이전글 <img src="<?php echo $board_skin_url ?>/img/arr_prev.png" title="이전글"></td>  <td scope="col" class="td_subject" style="padding-left:10px;"><?php if ($prev_href) { ?><a href="<?php echo $prev_href ?>"><?php echo $prev_wr_subject; ?></a><?php }  else { ?>등록된 게시물이 없습니다<?php } ?></td>  <td scope="col" style="text-align:center; width:80px;"><?php if ($prev_href) echo date("Y-m-d", strtotime($prev['wr_datetime'])) ?></td>        </tr>        <tr>  <td scope="col" bgcolor=#f4f4f4 style="text-align:center; width:100px;">다음글 <img src="<?php echo $board_skin_url ?>/img/arr_next.png" title="다음글"></td>  <td scope="col" class="td_subject" style="padding-left:10px;"><?php if ($next_href) { ?><a href="<?php echo $next_href ?>"><?php echo $next_wr_subject; ?></a><?php }  else { ?>등록된 게시물이 없습니다<?php } ?></td>  <td scope="col"  style="text-align:center; width:80px;"><?php if ($next_href) echo date("Y-m-d", strtotime($next['wr_datetime'])) ?></td>        </tr>  </table> </div>    <!-- } 이전글 다음글 끝 -->