public void walk(){
		switch (walktype) {
		case GO_LEFT:
			speedX = DEFAULT_SPEED_LEFT;
			speedY = 0;
			break;
		case GO_RIGHT:
			speedX = DEFAULT_SPEED_RIGHT;
			speedY = 0;
			break;
		case GO_UP:
			speedX = 0;
			speedY = DEFAULT_SPEED_UP;
			break;
		case GO_DOWN:
			speedX = 0;
			speedY = DEFAULT_SPEED_DOWN;
			break;
		}
	}