<?php

include 'db_connect.php';
include 'iconv_encodeing.php';
include 'user_name_converter.php';
$room_number = iconv_encodeing($_GET["room_number"]);
$user_name = iconv_encodeing($_GET["user_name"]);
$user_id = user_name_to_user_id($user_name);
mysql_query("delete from participated_room where room_number = {$room_number} and participated_user_id = {$user_id}") or die("failed you can't go out");
echo "Succeed";
<?php

include 'db_connect.php';
include 'iconv_encodeing.php';
include 'user_name_converter.php';
$room_number = iconv_encodeing($_GET["room_number"]);
$friend_name = iconv_encodeing($_GET["friend_name"]);
$friend_id = user_name_to_user_id($friend_name);
mysql_query("insert into participated_room(room_number,participated_user_id) values ('{$room_number}','{$friend_id}')") or die("failed");
echo "Succeed";