@Override
	public void keyReleased(KeyEvent ke) {
		if (isStart) {
			switch (ke.getKeyCode()) {
			// 停止向右移动
			case KeyEvent.VK_D:
				mario.rightStop();
				break;

			// 停止向左移动
			case KeyEvent.VK_A:
				mario.leftStop();
				break;

			default:
				break;
			}
		} else {
			// press any key to start game!
			isStart = true;
			currBg.enemyStartMove();
			mario.setScore(0);
			mario.setLife(3);
		}

	}