Вот if ($set_mail['access'] == 2){
$query = mysql_query("SELECT * FROM `cms_contact` WHERE `user_id`='" . $id . "' AND `from_id`='" . $user_id . "' AND `friends`='1' LIMIT 1;");
if (mysql_num_rows($query) == 0) {
$error[] = $lng_mail['write_friends'];
}
}