'123456', 'guest' => 'abc123' ]; if ($_SERVER['REQUEST_METHOD'] === 'POST') { $user = $_POST['username'] ?? ''; $pass = $_POST['password'] ?? ''; if (isset($users[$user]) && $users[$user] === $pass) { $_SESSION['user'] = $user; } else { $error = "Retcode : 0"; } } if (isset($_GET['logout'])) { unset($_SESSION['user']); } ?>