메인 가운데 정렬 오류좀요..

head.sub.php

<div align="center">
이거 넣었구요

tail.php
</div>

이거 넣었더니


아래 오류가 납니다..ㅜㅜ 해결법좀 알려주세요
Warning: Cannot modify header information - headers already sent by (output started at /home/solbase73/www/head.sub.php:1) in /home/solbase73/www/head.sub.php on line 32

Warning: Cannot modify header information - headers already sent by (output started at /home/solbase73/www/head.sub.php:1) in /home/solbase73/www/head.sub.php on line 34

Warning: Cannot modify header information - headers already sent by (output started at /home/solbase73/www/head.sub.php:1) in /home/solbase73/www/head.sub.php on line 35

Warning: Cannot modify header information - headers already sent by (output started at /home/solbase73/www/head.sub.php:1) in /home/solbase73/www/head.sub.php on line 36

Warning: Cannot modify header information - headers already sent by (output started at /home/solbase73/www/head.sub.php:1) in /home/solbase73/www/head.sub.php on line 37

Warning: Cannot modify header information - headers already sent by (output started at /home/solbase73/www/head.sub.php:1) in /home/solbase73/www/head.sub.php on line 38