코드 입력시 이동하는 페이지인데 코드값을 바꿀 수 있을까요?

<?php

include_once('./_common.php');

 

$g5['title'] = "프로모션 검사";

 

$ev_id       = isset($_POST['ev_id']) ? trim($_POST['ev_id']) : '';

$ev_p_code = isset($_POST['ev_p_code']) ? trim($_POST['ev_p_code']) : '';

 

if (!$ev_id || !$ev_p_code) alert('프로모션 코드를 입력해 주세요.');

 

$sql = " select * from {$g5['g5_shop_event_table']}

          where ev_id = '$ev_id'

            and ev_use = 1 and ev_promo = '1' ";

$ev = sql_fetch($sql);

if (! (isset($ev['ev_id']) && $ev['ev_id'])) alert('등록된 프로모션이 없습니다.');


 

if($ev['ev_p_code'] == $ev_p_code)

{

    set_session('ss_promo_'.$ev['ev_id'], $ev_p_code);

    goto_url("/shop/promotion.php?ev_id=".$ev_id);

}

else{

    alert("프로모션 코드가 일치하지 않습니다.");

}

<?php

include_once('./_common.php');

 

$ev_id = isset($_GET['ev_id']) ? (int) $_GET['ev_id'] : 0;

 

include_once('./_head.php');

 

if($ev_id == 0)

{

    alert("올바른 방법으로 이용해주세요.", "/");

    exit;

}

 

$sql = " select * from {$g5['g5_shop_event_table']}

          where ev_id = '$ev_id'

            and ev_use = 1 and ev_promo = '1' ";

$ev = sql_fetch($sql);

 

if (! (isset($ev['ev_id']) && $ev['ev_id'])) alert('등록된 프로모션이 없습니다.', "/");

 

?>

 

<style type="text/css">

.code_area { padding: 120px 0; background: #f7f7f7; }

.code_area .cd_box { width: 700px; margin: 0 auto; overflow: hidden; border-radius:6px; background: #Fff; box-shadow: 0px 3px 4px 4px #0000000d; }

.code_area .cd_box .con { text-align:center; }

.code_area .cd_box p { padding:60px 0 0px; font-size: 20px; }

.code_area .cd_box .inp { width: 80%; border: 2px solid #f5f3f3;  padding: 16px 30px; border-radius: 4px; font-size:30px; background: #f9f9f9; }

.code_area .cd_box .inp::placeholder { color: #bbb; }

.code_area .cd_box button { display: block; width:100%; padding: 20px 0; margin-top:60px; color: #fff; background: #212a2f; }

 

@media screen and (max-width:800px) {

    .code_area .cd_box { width:80%; }

    .code_area .cd_box .con { padding:0; }

    .code_area .cd_box p { padding: 30px 0 0px; font-size: 16px; }

    .code_area .cd_box .inp { font-size:15px; }

    .code_area .cd_box button { width:100%;  margin-top:40px; }

}

 

</style>


 

<!-- code -->

<div class="code_area">    

    <div class="cd_box">  

        <div class="img"><img src="/css/images/img_code.png" alt=""></div>      

        <form name="flogin" action="./code_chk.php" method="post">

        <input type="hidden" name="ev_id" value="<?=$ev_id?>">

        <div class="con">

            <p><?=$ev["ev_subject"]?></p>

            <input type="text" class="inp" name="ev_p_code" placeholder="코드번호를 입력해주세요.">

            <button type="submit">확인</button>

        </div>      

        </form>

    </div>    

</div>

<!-- //code -->

 

<?php

include_once('./_tail.php');