http://sir.co.kr/bbs/board.php?bo_table=g4_tiptech&wr_id=2009&sca=&sfl=wr_subject||wr_content&stx=레벨&sop=and
아쵸오님이 올려주신 팁을 적용해보니 에러가 나오더라구요..

Warning: Cannot modify header information - headers already sent by (output started at /home/...../extend/level.php:41) in /home/...../head.sub.php on line 44

Warning: Cannot modify header information - headers already sent by (output started at /home/...../extend/level.php:41) in /home/...../head.sub.php on line 46

Warning: Cannot modify header information - headers already sent by (output started at /home/...../extend/level.php:41) in /home/...../head.sub.php on line 47

Warning: Cannot modify header information - headers already sent by (output started at /home/...../extend/level.php:41) in /home/...../head.sub.php on line 48

Warning: Cannot modify header information - headers already sent by (output started at /home/...../extend/level.php:41) in /home/...../head.sub.php on line 49

Warning: Cannot modify header information - headers already sent by (output started at /home/...../extend/level.php:41) in /home/...../head.sub.php on line 50

이런 에러가 나옵니다..
extend 폴더안에 level.php란 파일을 만들어서 그곳에 팁을 적용하고, bbs/login_check.php에 적용을 했는데 위와같은 에러가 나오네요..

뭘 잘못한걸까요??ㅜㅜ