phpbb_default_captcha::delete_code() takes no argument but uses $confirm_id

	function delete_code()

	{

		global $db, $user;

		$sql = 'DELETE FROM ' . CONFIRM_TABLE . "

			WHERE confirm_id = '" . $db->sql_escape($confirm_id) . "'

				AND session_id = '" . $db->sql_escape($user->session_id) . "'

				AND confirm_type = " . $this->type;

		$db->sql_query($sql);

	}