private void checkInput(){
		switch(state){
		case INTRO:
			if (Keyboard.isKeyDown(Keyboard.KEY_S))
				state = State.MAIN_MENU;
			if (Keyboard.isKeyDown(Keyboard.KEY_ESCAPE)){
				Display.destroy();
				System.exit(0);
			}
			break;
		case GAME:
			if (Keyboard.isKeyDown(Keyboard.KEY_BACK))
				state = State.MAIN_MENU;
			break;
		case MAIN_MENU:
			if (Keyboard.isKeyDown(Keyboard.KEY_RETURN))
				state = State.GAME;
			if (Keyboard.isKeyDown(Keyboard.KEY_I))
				state = State.INTRO;
			break;
		}
	}