public static void sortStudentsPromotion(int mode) {
		if (sList.isEmpty()) {
			System.out.println("There is no Student !");

		} else if (pList.isEmpty()) {
			System.out.println("There is no Promotion !");

		} else {

			System.out.println("Which promotion do you want ?");
			displayPromotionList();
			Scanner scIndexP = new Scanner(System.in);

			Promotion p = null;
			while (p == null) {
				int iP = scIndexP.nextInt();
				p = choosePromotionList(iP);
			}

			if (mode == 0) {
				p.sort(0);
				System.out.println(p);
			} else {
				p.sort(1);
				System.out.println(p);
			}
		}

	}