public static void addBook(Messagable ui, String isbn, String category, String author, String title, float dailyLateFee, float maxLateFee, int numberOfCopies){
		boolean itemAdded = true;
		if(Book.bookExists(isbn)){
			itemAdded = false;
			ui.sendMessage("ERROR: Item already exists");
		}
		if(numberOfCopies < 1){
			itemAdded = false;
			ui.sendMessage("ERROR: Must have at least 1 copy.");
		}
		if(isbn.isEmpty()){
			itemAdded = false;
			ui.sendMessage("ERROR: Enter an isbn");
		}
		if(dailyLateFee < 0){
			itemAdded = false;
			ui.sendMessage("ERROR: Enter a Daily Late Fee");
		}
		if(maxLateFee < dailyLateFee){
			itemAdded = false;
			ui.sendMessage("ERROR: Max Late Fee must be less than Daily Late Fee");
		}
		if(maxLateFee < 0){
			itemAdded = false;
			ui.sendMessage("ERROR: Enter a Max Late Fee");
		}
		if(itemAdded){
			Book.addBook(isbn, category, title, author, dailyLateFee, maxLateFee, numberOfCopies);
			ui.sendMessage("SUCCESS: Book added to database");
		}
	}