외부로그인 달면 이래 뜨는데 왜그런가요?ㅠㅠ

Warning: Cannot modify header information - headers already sent by (output started at D:\APM_Setup\htdocs\main.php:9) in D:\APM_Setup\htdocs\gnuboard4\common.php on line 8

Warning: Cannot modify header information - headers already sent by (output started at D:\APM_Setup\htdocs\main.php:9) in D:\APM_Setup\htdocs\gnuboard4\head.sub.php on line 32

Warning: Cannot modify header information - headers already sent by (output started at D:\APM_Setup\htdocs\main.php:9) in D:\APM_Setup\htdocs\gnuboard4\head.sub.php on line 34

Warning: Cannot modify header information - headers already sent by (output started at D:\APM_Setup\htdocs\main.php:9) in D:\APM_Setup\htdocs\gnuboard4\head.sub.php on line 35

Warning: Cannot modify header information - headers already sent by (output started at D:\APM_Setup\htdocs\main.php:9) in D:\APM_Setup\htdocs\gnuboard4\head.sub.php on line 36

Warning: Cannot modify header information - headers already sent by (output started at D:\APM_Setup\htdocs\main.php:9) in D:\APM_Setup\htdocs\gnuboard4\head.sub.php on line 37

Warning: Cannot modify header information - headers already sent by (output started at D:\APM_Setup\htdocs\main.php:9) in D:\APM_Setup\htdocs\gnuboard4\head.sub.php on line 38

외부로그인 창은 뜨긴 한데 이런 현상이...
외부로그인 달린 페이지는

<?
$g4_path="./gnuboard4";
include_once("./gnuboard4/common.php");
include_once("./gnuboard4/head.sub.php");
include_once("./gnuboard4/lib/outlogin.lib.php"); // outlogin() 함수를 사용하여야 하므로 이 프로그램을 포함시킵니다.

echo outlogin("basic"); // basic 스킨으로 아웃로그인을 출력합니다.
?>

이렇게 짰구요...

http://twoesv.wowip.kr:8080/

이 홈페이지인데 해결방법좀 알려주세요 ㅠㅠ