서버이전 후 관리자 페이지에 다음과 같은 오류가 뜹니다.

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Warning: Cannot modify header information - headers already sent by (output started at /www/도메인.com/y/w/a/ywam/htdocs/common.php:1) in /www/도메인.com/y/w/a/ywam/htdocs/head.sub.php on line 56

Warning: Cannot modify header information - headers already sent by (output started at /www/도메인.com/y/w/a/ywam/htdocs/common.php:1) in /www/도메인.com/y/w/a/ywam/htdocs/head.sub.php on line 58

Warning: Cannot modify header information - headers already sent by (output started at /www/도메인.com/y/w/a/ywam/htdocs/common.php:1) in /www/도메인.com/y/w/a/ywam/htdocs/head.sub.php on line 59

Warning: Cannot modify header information - headers already sent by (output started at /www/도메인.com/y/w/a/ywam/htdocs/common.php:1) in /www/도메인.com/y/w/a/ywam/htdocs/head.sub.php on line 60

Warning: Cannot modify header information - headers already sent by (output started at /www/도메인.com/y/w/a/ywam/htdocs/common.php:1) in /www/도메인.com/y/w/a/ywam/htdocs/head.sub.php on line 61

Warning: Cannot modify header information - headers already sent by (output started at /www/도메인.com/y/w/a/ywam/htdocs/common.php:1) in /www/도메인.com/y/w/a/ywam/htdocs/head.sub.php on line 62


어떻게 해결해야 하는지요?

에러페이지의 내용은 다음과 같습니다.

common.php
2      /*******************************************************************************
3        ** 공통 변수, 상수, 코드
4      *******************************************************************************/

head.sub.php
53    자바스크립트에서 go(-1) 함수를 쓰면 폼값이 사라질때 해당 폼의 상단에 사용하면
54    캐쉬의 내용을 가져옴. 완전한지는 검증되지 않음
55    header("Content-Type: text/html; charset=$g4[charset]");
56    $gmnow = gmdate("D, d M Y H:i:s") . " GMT";
57    header("Expires: 0"); // rfc2616 - Section 14.21
58    header("Last-Modified: " . $gmnow);
59    header("Cache-Control: no-store, no-cache, must-revalidate"); // HTTP/1.1
60    header("Cache-Control: pre-check=0, post-check=0, max-age=0"); // HTTP/1.1
61    header("Pragma: no-cache"); // HTTP/1.0
62    ?>