이 소스 해석 좀 해주실분ㅠㅠㅠ 채택완료

저두잘몰라서 대충 아는부분만... 

$subsql = "    select MAX(A.wr_id) as m_wr_id, A.ca_name as m_ca_name from    (    SELECT wr_id, ca_name FROM $g5[write_prefix]$bo_table $where $andless    UNION ALL    SELECT 0 as wr_id, 'Book' as ca_name    UNION ALL    SELECT 0 as wr_id, 'Magazine' as ca_name    UNION ALL    SELECT 0 as wr_id, 'Brochure' as ca_name    UNION ALL    SELECT 0 as wr_id, 'Catalogue' as ca_name    UNION ALL    SELECT 0 as wr_id, 'Annual+Report' as ca_name    UNION ALL    SELECT 0 as wr_id, 'Poster' as ca_name    UNION ALL    SELECT 0 as wr_id, 'C.I' as ca_name    UNION ALL    SELECT 0 as wr_id, 'Customizing' as ca_name   ) A   GROUP BY A.ca_name   ORDER BY A.wr_id DESC  ";

 $subrow = sql_fetch($subsql); //쿼리문의 셀렉트 값을 $subrow 에 저장

 if(!$wr_id) {                     //만약에 $wr_id 가 없으면   if ($_GET[sca] == "")        //만약에   $_GET[sca] 값이 ""(공백)일때   {    goto_url("./board.php?bo_table=$bo_table&sca=$sca&wr_id=$subrow[m_wr_id]"); //페이지이동    } else {                                                                    //아니면    $subresult = sql_query($subsql);                          //쿼리문의 셀렉트 값을 $subrow 에 저장    while($subrow = sql_fetch_array($subresult))            //쿼리문의 인덱스 값까지 반복문    {     if ($_GET[sca] == $subrow[m_ca_name])  // 만약 ($_GET[sca] 값이 $subrow[m_ca_name] 같다면     {      if ($subrow[m_wr_id]!=0) goto_url("./board.php?bo_table=$bo_table&sca=$sca&wr_id=$subrow[m_wr_id]");// 만약에 $subrow[m_wr_id]값이 0이면  ./board.php?bo_table=$bo_table&sca=$sca&wr_id=$subrow[m_wr_id] 여기로 페이지 이동     }    }   }   } else if ($write_href) { // 분명 밑에 더있을텐데요