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