public void run() {
		while (true) {
			if (this.bg.isOver()) {
				if (this.y < 420) {
					this.y += 5;
				} else {
					this.bg.setDown(true);
				}
			}

			try {
				Thread.sleep(50);
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
		}
	}