public void book_delete() throws Exception{

		Book deletebook = bookcollect.book_search_lib(); 
		//  ˻Ѵ.
		System.out.println(" Ͻðڽϱ?(Y/N)");
		scan.nextLine();

		String deletecheck = scan.nextLine();

		if (deletecheck.equals("Y")) {
			bookcollect.delete(deletebook);
			librarian_menu();
		} 
		else if (deletecheck.equals("N")) {
			librarian_menu();
		}
	}