게시글 정렬방법에서 최근 1시간이내 글만 보여주는 방법이 궁금합니다. 채택완료

</p><p><option value="wr_datetime asc" <?php echo get_selected($board['bo_sort_field'], "wr_datetime asc"); ?>>wr_datetime asc : 날짜 이전것 부터</option>
                    <option value="wr_hit desc, wr_num, wr_reply" <?php echo get_selected($board['bo_sort_field'], "wr_hit desc, wr_num, wr_reply"); ?>>wr_hit desc : 조회수 높은것 부터</option>
                    <option value="wr_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>​</p><p>