public boolean buyDVD(int n) {
		try {
			if (this.money >= dateHandle.get(n).getBuyPrice()) {
				// Ǯ
				if (dateHandle.get(n).sellOne()) {
					// 
					this.addBuyDate(dateHandle.get(n).getTitle(), dateHandle.get(n).getID());
					return true;
				}
			}
		} catch (Exception e) {
			return false;
		}
		return false;
	}