이 글은 질답게시판에 올라온 글중에 회원가입시 중복확인 후 다시 가입폼으로 돌아올 경우 새로 써야 되는 번거로움을 말씀하신분이 계시길래 간단히 적어봅니다.

check_user_id.php 를 다음과 같이 수정하시면 됩니다.

<?
  $user_id = htmlspecialchars(trim($_GET['user_id']));

  include "lib.php";
  $user_id = strtolower(trim($user_id));
  $connect=dbconn();
  $check=mysql_fetch_array(mysql_query("select count(*) from $member_table where user_id='$user_id'"));
  mysql_close($connect);
  head();
?>
<script>
function insertId(iValid) {

        if(iValid == 1) {

                self.close();

        } else {

                opener.write.user_id.value = '<?=$user_id?>';
                opener.write.useridCheck.value = '<?=$user_id?>';
                self.close();

        }

}
</script>
<table border=0 width=100% height=100%>
<tr>
  <td align=center>
<?
if($check[0]) {

        $useridValue = 1;
        echo "$user_id 는 이미 등록된<br> 아이디입니다";

} else {
        
        $useridValue = 2;
        echo"$user_id 는 사용하실수 있습니다";

}
?>

</td>
</tr>
<form>
<tr>
  <td align=center><input type=button value='Close window' onclick='insertId(<?=$useridValue?>)' class=submit></td>
</tr>
</form>
</table>

<?
         @mysql_close($connect);
         foot();
?>

-----------------------------------------------------------

check_user_email.php 를 제로보드가 설치된 곳에 다음과 같이 작성해주세요.

<?
  $user_email = htmlspecialchars(trim($_GET['email']));

  include "lib.php";
  $user_email = strtolower(trim($user_email));
  $connect=dbconn();
  $check=mysql_fetch_array(mysql_query("select count(*) from $member_table where email='$user_email'"));
  mysql_close($connect);
  head();
?>

<script>
function insertEmail(eValid) {

        if(eValid == 1) {

                self.close();

        } else {

                opener.write.email.value = '<?=$user_email?>';
                opener.write.emailCheck.value = '<?=$user_email?>';
                self.close();

        }

}
</script>
<table border=0 width=100% height=100%>
<tr>
  <td align=center>
<?
        if($check[0]) {
                
                $emailUse = 1;
                echo "$user_email 은 이미 등록된<br> 이메일입니다";

        } else {

                $emailUse = 2;
                echo"$user_email 은 사용하실수 있습니다";

        }
?>

</td>
</tr>
<form>
<tr>
  <td align=center><input type=button value='Close window' onclick="insertEmail(<?=$emailUse?>)" class=submit></td>
</tr>
</form>
</table>

<?
         @mysql_close($connect);
         foot();
?>

---------------------------------------------------------------------------

member_join.php 를 다음처럼 수정합니다.

<?
// 라이브러리 함수 파일 인크루드
        include "lib.php";

// DB 연결
        if(!$connect) $connect=dbConn();

// 그룹 번호 체크
        if(!$group_no) {
                $tmpResult = mysql_fetch_array(mysql_query("select * from $group_table order by no limit 1"));
                $group_no = $tmpResult[no];
        }

// 멤버 정보 구해오기;;; 멤버가 있을때
        $member=member_info();

        if($mode=="admin"&&($member[is_admin]==1||($member[is_admin]==2&&$member[group_no]==$group_no))) $mode = "admin";
        else $mode = "";

        if($member[no]&&!$mode) Error("이미 가입이 되어 있습니다.","window.close");


// 게시판과 그룹설정에 따라서 회원 가입 설정
        if($id) {
                // 현재 게시판 설정 읽어 오기
                $setup=get_table_attrib($id);

                // 설정되지 않은 게시판일때 에러 표시
                if(!$setup[name]) Error("생성되지 않은 게시판입니다.<br><br>게시판을 생성후 사용하십시요","window.close");

                // 현재 게시판의 그룹의 설정 읽어 오기
                $group=group_info($setup[group_no]);
                if(!$group[use_join]&&!$mode) Error("현재 지정된 그룹은 추가 회원을 모집하지 않습니다","window.close");

        } else {

                if($group_name) $group=mysql_fetch_array(mysql_query("select * from $group_table where name='$group_name'"));
                elseif($group_no) $group=mysql_fetch_array(mysql_query("select * from $group_table where no='$group_no'"));
                if(!$group[no]) Error("지정된 그룹이 존재하지 않습니다");
                if(!$group[use_join]&&!$mode) Error("현재 지정된 그룹은 추가 회원을 모집하지 않습니다");

        }

        $check[1]="checked";

        if(!$referer) $referer=$HTTP_REFERER;

        $setup[header]="";
        $setup[footer]="";
        $setup[header_url]="";
        $setup[footer_url]="";
        $group[header]="";
        $group[footer]="";
        $group[header_url]="";
        $group[footer_url]="";
        $setup[skinname]="";

        head();

        echo "<div align=center><br>";
?>

<script>
function address_popup(num)
{
  window.open('zipcode/search_zipcode.php?num='+num,'searchaddress','width=440,height=230,scrollbars=yes');
}

function check_submit()
{

<?
        if(file_exists("./join_license.txt")) {
?>

  if(!write.accept.checked) {
        alert("가입약관에 동의하셔야 회원가입을 할수 있습니다");
        return false;
  }

<?
        }
?>

  if(!write.user_id.value) {alert("아이디를 입력하여 주십시요.");write.user_id.focus(); return false;}
  if(write.useridCheck.value == '') {alert('아이디 중복확인을 해주세요.');write.user_id.focus(); return false;}
  if(write.user_id.value != write.useridCheck.value) {alert("아이디 중복확인을 해주세요.");write.user_id.focus(); return false;

<?
        if($_zbDefaultSetup[enable_hangul_id]=="false") {
?>

  // ID Check
  if(write.user_id.value.length<4||write.user_id.value.length>40) {
    alert("아이디는 4자 이상, 40자 이하여야 합니다.");
    write.user_id.focus();
    return false;
  }
  var valid = "abcdefghijklmnopqrstuvwxyz0123456789_";
  var startChar = "abcdefghijklmnopqrstuvwxyz";
  var temp;
  write.user_id.value = write.user_id.value.toLowerCase();
  temp = write.user_id.value.substring(0,1);
  if (startChar.indexOf(temp) == "-1") {
    alert("아이디의 첫 글자는 영문이어야 합니다.");
    write.user_id.value = "";
    write.user_id.focus();
    return false;
  }
  for (var i=0; i<write.user_id.value.length; i++) {
    temp = "" + write.user_id.value.substring(i, i+1);
    if (valid.indexOf(temp) == "-1") {
      alert("아이디는 영문과 숫자, _ 로만 이루어질수 있습니다.");
      write.user_id.value = "";
      write.user_id.focus();
      return false;
    }
  }
<?
        }
?>

  if(!write.password.value) {alert("비밀번호를 입력하여 주십시요.");write.password.focus(); return false;}
  if(!write.password1.value) {alert("비밀번호 확인을 입력하여 주십시요.");write.password1.focus(); return false;}
  if(write.password.value!=write.password1.value) {alert("패스워드가 일치하지 않습니다.");write.password.value="";write.password1.value=""; write.password.focus(); return false;}
  if(!write.name.value) { alert("이름을 입력하세요"); write.name.focus(); return false; }

<? if($group[use_birth])
   { ?>

    if ( write.birth_1.value < 1000 || write.birth_1.value <= 0 )  {
         alert('생년이 잘못입력되었습니다.');
         write.birth_1.value='';
         write.birth_1.focus();
        return false;
    }
    if ( write.birth_2.value > 12 || write.birth_2.value <= 0 ) {
         alert('생월이 잘못입력되었습니다.');
         write.birth_2.value='';
         write.birth_2.focus();
        return false;
    }
    if ( write.birth_3.value > 31 || write.birth_3.value <= 0 )  {
         alert('생일이 잘못입력되었습니다.');
         write.birth_3.value='';
         write.birth_3.focus();
        return false;
    }
<? } ?>
  if(!write.email.value) {alert("E-Mail을 입력하여 주십시요.");write.email.focus(); return false;}
  if(write.emailCheck.value == '') {alert('E-Mail 중복확인을 해주세요.');write.email.focus(); return false;}
  if(write.email.value != write.emailCheck.value) {alert("E-Mail 중복확인을 해주세요.");write.email.focus(); return false;

<? if($group[use_jumin]&&!$mode)
   { ?>
   if(!write.jumin1.value) {alert("주민등록번호를 입력하여 주십시요");write.jumin1.focus(); return false;}
   if(!write.jumin2.value) {alert("주민등록번호를 입력하여 주십시요");write.jumin2.focus(); return false;}
<?}?>

  return true;
  }

  function check_id(id)
  {
   if(!id)
   {
    alert('아이디를 입력하여 주십시요');
   }
   else
   {
    window.open('check_user_id.php?user_id='+id,'check_user_id','width=200,height=100,toolbar=no,status=no,resizable=no');
   }
  }

  function check_email(email)
  {
   if(!email)
   {
    alert('이메일을 입력하여 주십시요');
   }
   else
   {
    window.open('check_user_email.php?email='+email,'check_user_email','width=200,height=100,toolbar=no,status=no,resizable=no');
   }
  }

  function check_accept() {
        return confirm("위의 가입 약관을 모두 보았으며, 동의하십니까?");
  }

</script>
<table border=0 cellspacing=1 cellpadding=0 width=540>
<form name=write method=post action=member_join_ok.php enctype=multipart/form-data onsubmit="return check_submit();">
<input type=hidden name=useridCheck value=''>
<input type=hidden name=emailCheck value=''>
<input type=hidden name=id value=<?=$id?>>
<input type=hidden name=referer value="<?=$referer?>">
<input type=hidden name=group_no value="<?=$group[no]?>">
<input type=hidden name=mode value="<?=$mode?>">

  <tr><td colspan=2><img src=images/member_joinin.gif><br><br></td></tr>

<?
        if(file_exists("./join_license.txt")) {
                $f=fopen("join_license.txt",r);
                $join_license = fread($f,filesize("join_license.txt"));
                fclose($f);
?>
  <tr><td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="3"></td></tr>
  <tr>
          <td colspan=2>
                  <br><div align=center><textarea cols=80 rows=6 readonly style=border-color:#d8b3b3;width:95% class=input><?=$join_license?></textarea></div>
        </td>
  </tr>
  <tr>
          <td colspan=2>   <input type=checkbox name=accept value=1 onclick="return check_accept()"> 위의 가입 약관에 동의합니다</td>
  </tr>
<?
        }
?>
        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="3"></td>
        </tr>
  <tr align=right>
     <td width=25% style=font-family:Tahoma;font-size:8pt;><b>ID </td>
     <td align=left> <input type=text name=user_id size=20 maxlength=20 style=border-color:#d8b3b3 class=input> <input type=button value='Check ID' style=color:#000000;border-color:#dfb8b8;background-color:#f0f0f0;font-size:8pt;font-family:Tahoma;height:20px; onclick=check_id(write.user_id.value)><br><img src=images/t.gif border=0 height=4><? if($_zbDefaultSetup[enable_hangul_id]=="false") {?><br> (영문,숫자,_로만 아이디를 작성하세요)<? } ?></td>
  </tr>
        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>
  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt;><B>Password </td>
     <td align=left> <input type=password name=password size=20 maxlength=20 style=border-color:#d8b3b3 class=input> 확인 : <input type=password name=password1 size=20 maxlength=20 style=border-color:#d8b3b3 class=input></td>
  </tr>
        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>
  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt;><b>Name </td>
     <td align=left> <input type=text name=name size=20 maxlength=20 value="<?=$member[name]?>" style=border-color:#d8b3b3 class=input></td>
  </tr>
        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>
<? if($group[use_birth]) { ?>
  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt;><b>Birthday </td>
     <td align=left> <input type=text name=birth_1 size=4 maxlength=4 style=border-color:#d8b3b3 class=input> 년
                     <input type=text name=birth_2 size=2 maxlength=2 style=border-color:#d8b3b3 class=input> 월
                     <input type=text name=birth_3 size=2 maxlength=2 style=border-color:#d8b3b3 class=input> 일
          <input type=checkbox value=1 checked name=open_birth> 공개
  </tr>        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>
<? } ?>

  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt;><b>E-mail </td>
     <td align=left> <input type=text name=email size=50 maxlength=255 value="<?=$member[email]?>" style=border-color:#d8b3b3 class=input> <input type=button value='Check EMAIL' style=color:#000000;border-color:#dfb8b8;background-color:#f0f0f0;font-size:8pt;font-family:Tahoma;height:20px; onclick=check_email(write.email.value)>
                          <input type=checkbox value=1 name=open_email checked> 공개
                          </td>
  </tr>        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>
  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt;>Homepage </td>
     <td align=left> <input type=text name=homepage size=50 maxlength=255 value="<?=$member[homepage]?>" style=border-color:#d8b3b3 class=input>
                          <input type=checkbox value=1 name=open_homepage checked> 공개</td>
  </tr>        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>

<? if($group[use_icq]) { ?>
  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt;>ICQ </td>
     <td align=left> <input type=text name=icq size=20 maxlength=20 value="<?=$member[icq]?>" style=border-color:#d8b3b3 class=input>
                          <input type=checkbox value=1 name=open_icq checked> 공개</td>
  </tr>        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>
<? } ?>

<? if($group[use_aol]) { ?>
  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt;>AIM </td>
     <td align=left> <input type=text name=aol size=20 maxlength=20 value="<?=$member[aol]?>" style=border-color:#d8b3b3 class=input>
                          <input type=checkbox value=1 name=open_aol checked> 공개</td>
  </tr>        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>
<? } ?>

<? if($group[use_msn]) { ?>
  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt;>MSN </td>
     <td align=left> <input type=text name=msn size=20 maxlength=250 value="<?=$member[msn]?>" style=border-color:#d8b3b3 class=input>
                          <input type=checkbox value=1 name=open_msn checked> 공개</td>
  </tr>        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>
<? } ?>

<? if($group[use_jumin]) { ?>
  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt; valign=top><table border=0 cellspacing=0 cellpadding=0 height=4><tr><td></td></tr></table><b>주민등록번호  </td>
     <td align=left> <input type=text name=jumin1 size=6 maxlength=6 style=border-color:#d8b3b3 class=input>-<input type=text name=jumin2 size=7 maxlength=7 style=border-color:#d8b3b3 class=input> <br>* 주민등록번호는 암호화되어 저장이 되므로 관리자도 알수 없습니다<br>
       (회원 중복가입을 막기 위한 검사수단으로만 사용이 됩니다)</td>
  </tr>        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>
<? } ?>

<? if($group[use_hobby]) { ?>
  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt;>Hobby </td>
     <td align=left> <input type=text name=hobby size=50 maxlength=50 value="<?=$member[hobby]?>" style=border-color:#d8b3b3 class=input>
                          <input type=checkbox value=1 name=open_hobby checked> 공개</td>
  </tr>        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>
<? } ?>

<? if($group[use_job]) { ?>
  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt;>Occupation(Job) </td>
     <td align=left> <input type=text name=job size=20 maxlength=20 value="<?=$member[job]?>" style=border-color:#d8b3b3 class=input>
                          <input type=checkbox value=1 name=open_job checked> 공개</td>
  </tr>        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>
<? } ?>

<? if($group[use_home_address]) { ?>
  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt;>Home Address </td>
     <td align=left> <input type=text name=home_address size=40 maxlength=255 value="<?=$member[home_address]?>" style=border-color:#d8b3b3 class=input><input type=button value='검색' class=input style=border-color:#d8b3b3 onclick=address_popup(1)>
                          <input type=checkbox value=1 name=open_home_address checked> 공개</td>
  </tr>        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>
<? } ?>

<? if($group[use_home_tel]) { ?>
  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt;>Home Phone </td>
     <td align=left> <input type=text name=home_tel size=20 maxlength=20 value="<?=$member[home_tel]?>" style=border-color:#d8b3b3 class=input>
                          <input type=checkbox value=1 name=open_home_tel checked> 공개</td>
  </tr>        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>
<? } ?>

<? if($group[use_office_address]) { ?>
  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt;>Office Address </td>
     <td align=left> <input type=text name=office_address size=40 maxlength=255 value="<?=$member[office_address]?>" style=border-color:#d8b3b3 class=input><input type=button value='검색' class=input style=border-color:#d8b3b3 onclick=address_popup(2)>
                          <input type=checkbox value=1 name=open_office_address checked> 공개</td>
  </tr>        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>
<? } ?>

<? if($group[use_office_tel]) { ?>
  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt;>Office Phone </td>
     <td align=left> <input type=text name=office_tel size=20 maxlength=20 value="<?=$member[office_tel]?>" style=border-color:#d8b3b3 class=input>
                          <input type=checkbox value=1 name=open_office_tel checked> 공개</td>
  </tr>        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>
<? } ?>

<? if($group[use_handphone]) { ?>
  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt;>Cellular </td>
     <td align=left> <input type=text name=handphone size=20 maxlength=20 value="<?=$member[handphone]?>" style=border-color:#d8b3b3 class=input>
                          <input type=checkbox value=1 name=open_handphone checked> 공개</td>
  </tr>        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>
<? } ?>

<? if($group[use_mailing]) { ?>
  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt;><b>Mailling List </td>
     <td align=left> <input type=checkbox name=mailing value=1 checked> 메일링 가입</td>
  </tr>        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>
<? } ?>

<? if($group[use_picture]) { ?>
  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt;>Photo </td>
     <td align=left> <input type=file name=picture size=35 maxlength=255 style=border-color:#d8b3b3 class=input>
                 <? if($member[picture]) echo"<br> <img src='$member[picture]' border=0>"; ?>
                          <input type=checkbox value=1 name=open_picture checked> 공개
     </td>
  </tr>        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>
<? } ?>

<? if($group[use_comment]) { ?>
  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt;>자기 소개서</td>
     <td align=left> <textarea cols=50 rows=4 name=comment style=border-color:#d8b3b3 class=textarea><?=$member[comment]?></textarea><br> <input type=checkbox value=1 name=open_comment checked> 공개</td>

  </tr>        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>
<? } ?>

  <tr align=right height=28>
     <td style=font-family:Tahoma;font-size:8pt;><b>개인정보 공개</td>
     <td align=left> <input type=checkbox name=openinfo value=1 checked> 정보 공개</td>
  </tr>        <tr>
          <td colspan="5" bgcolor="#EBD9D9" align="center"><img src="images/t.gif" width="10" height="1"></td>
        </tr>

<tr height=30 bgcolor=#ffffff>
   <td  colspan=2 align=right ><img src=images/t.gif height=5><br>
   <input type=image border=0 src=images/button_join.gif>  
   <img src=images/memo_close.gif border=0 onClick=window.close() style=cursor:hand>   
   </td>
</tr>

  </form>
</table>


<?
        @mysql_close($connect);
        foot();
?>

사실 그리 바뀌는 부분은 거의 없습니다.
다만 이메일 아이디 체크창과 이메일 체크창을 띄우고 만약 중복확인 하지 않은 경우나 중복확인 후에 새로운 값을 입력한 경우 체크해서 다음으로 진행하지 못하도록 하는 부분만 추가했습니다.

즐거운 하루 되세요.