public void insert_to_bookList(Book _input){
		int ListSize = BookList.size();
		boolean found=false;
		if (ListSize == 0) {
			BookList.add(_input);
			System.out.println("Book Added!");
		}else{
		for (Book entry : BookList) {
		if (_input.CallNumber.equals(entry.CallNumber) && _input.bookYear.equals(entry.bookYear)) {
			System.out.println("\nSorry that book already exists");
			found = true;
			}
		}
		if (found != true){
		BookList.add(_input);
		System.out.println("Book Added!!!");
		}
	}
}