public boolean addDVD(String title, int year, ArrayList<Long> style, int amount, double buyPrice, double rentPrice) {
		// 
		for (DVD a : this.dVDMainDateArrayList) {
			if ( a.getTitle().equals(title) && a.getYear() == year ) {
				return false;
			}
		}
		boolean sell;
		if (amount > DVD.getSELL_LIMIT()) {
			sell = true;
		} else {
			sell = false;
		}
		boolean rent;
		if (amount > DVD.getRENT_LIMIT()) {
			rent = true;
		} else {
			rent = false;
		}
		dVDMainDateArrayList.add( new DVD(title, year, style, amount, sell, rent, buyPrice, rentPrice));
		return false;
	}