게시판에서 wr_4가 1이면 무족건 상단 에서부터 출력하고 입력 되지 않으면 날짜순으로 출력 되게 하고 싶습니다. 채택완료

</p><p>        <tr>
            <th scope="row"><label for="bo_sort_field">리스트 정렬 필드</label></th>
            <td>
                <?php echo help('리스트에서 기본으로 정렬에 사용할 필드를 선택합니다. "기본"으로 사용하지 않으시는 경우 속도가 느려질 수 있습니다.') ?>
                <select id="bo_sort_field" name="bo_sort_field">
                    <option value="" <?php echo get_selected($board['bo_sort_field'], ""); ?>>wr_num, wr_reply : 기본</option>
                    <option value="wr_datetime asc" <?php echo get_selected($board['bo_sort_field'], "wr_datetime asc"); ?>>wr_datetime asc : 날짜 이전것 부터</option>
                    <option value="wr_datetime desc" <?php echo get_selected($board['bo_sort_field'], "wr_datetime desc"); ?>>wr_datetime desc : 날짜 최근것 부터</option>
                    <option value="wr_hit asc, wr_num, wr_reply" <?php echo get_selected($board['bo_sort_field'], "wr_hit asc, wr_num, wr_reply"); ?>>wr_hit asc : 조회수 낮은것 부터</option>
                    <option value="wr_hit desc, wr_num, wr_reply" <?php echo get_selected($board['bo_sort_field'], "wr_hit desc, wr_num, wr_reply"); ?>>wr_hit desc : 조회수 높은것 부터</option>
                    <option value="wr_last asc" <?php echo get_selected($board['bo_sort_field'], "wr_last asc"); ?>>wr_last asc : 최근글 이전것 부터</option>
                    <option value="wr_last desc" <?php echo get_selected($board['bo_sort_field'], "wr_last desc"); ?>>wr_last desc : 최근글 최근것 부터</option>
                    <option value="wr_comment asc, wr_num, wr_reply" <?php echo get_selected($board['bo_sort_field'], "wr_comment asc, wr_num, wr_reply"); ?>>wr_comment asc : 댓글수 낮은것 부터</option>
                    <option value="wr_comment desc, wr_num, wr_reply" <?php echo get_selected($board['bo_sort_field'], "wr_comment desc, wr_num, wr_reply"); ?>>wr_comment desc : 댓글수 높은것 부터</option>
                    <option value="wr_good asc, wr_num, wr_reply" <?php echo get_selected($board['bo_sort_field'], "wr_good asc, wr_num, wr_reply"); ?>>wr_good asc : 추천수 낮은것 부터</option>
                    <option value="wr_good desc, wr_num, wr_reply" <?php echo get_selected($board['bo_sort_field'], "wr_good desc, wr_num, wr_reply"); ?>>wr_good desc : 추천수 높은것 부터</option>
                    <option value="wr_nogood asc, wr_num, wr_reply" <?php echo get_selected($board['bo_sort_field'], "wr_nogood asc, wr_num, wr_reply"); ?>>wr_nogood asc : 비추천수 낮은것 부터</option>
                    <option value="wr_nogood desc, wr_num, wr_reply" <?php echo get_selected($board['bo_sort_field'], "wr_nogood desc, wr_num, wr_reply"); ?>>wr_nogood desc : 비추천수 높은것 부터</option>
                    <option value="wr_subject asc, wr_num, wr_reply" <?php echo get_selected($board['bo_sort_field'], "wr_subject asc, wr_num, wr_reply"); ?>>wr_subject asc : 제목 오름차순</option>
                    <option value="wr_subject desc, wr_num, wr_reply" <?php echo get_selected($board['bo_sort_field'], "wr_subject desc, wr_num, wr_reply"); ?>>wr_subject desc : 제목 내림차순</option>
                    <option value="wr_name asc, wr_num, wr_reply" <?php echo get_selected($board['bo_sort_field'], "wr_name asc, wr_num, wr_reply"); ?>>wr_name asc : 글쓴이 오름차순</option>
                    <option value="wr_name desc, wr_num, wr_reply" <?php echo get_selected($board['bo_sort_field'], "wr_name desc, wr_num, wr_reply"); ?>>wr_name desc : 글쓴이 내림차순</option>
                    <option value="ca_name asc, wr_num, wr_reply" <?php echo get_selected($board['bo_sort_field'], "ca_name asc, wr_num, wr_reply"); ?>>ca_name asc : 분류명 오름차순</option>
                    <option value="ca_name desc, wr_num, wr_reply" <?php echo get_selected($board['bo_sort_field'], "ca_name desc, wr_num, wr_reply"); ?>>ca_name desc : 분류명 내림차순</option>
                </select>
            </td></p><p>

</p><p><option value="wr_4 desc, wr_num, wr_reply" <?php echo get_selected($board['bo_sort_field'], "wr_4 desc, wr_num, wr_reply"); ?>>wr_4 desc, wr_num, wr_reply : wr_4 입력 순</option></p><p>