static void Main(string[] args) { SuppliersController callSupplier = new SuppliersController(); ItemsController callItem = new ItemsController(); TransactionsController callTransaction = new TransactionsController(); Console.WriteLine("=========== Manage Data ============"); Console.WriteLine("1. Item"); Console.WriteLine("2. Supplier"); Console.WriteLine("3. Transaction"); Console.WriteLine("===================================="); Console.Write("Going to : "); int chance = Convert.ToInt32(Console.ReadLine()); Console.WriteLine("===================================="); if (chance == 1) { callItem.ManageItem(); } else if (chance == 2) { callSupplier.ManageSupplier(); } else if (chance == 3) { //callTransaction.ManageTransaction(); callTransaction.Print(); } else { Console.WriteLine("Something is wrong, please try again."); Console.Read(); } }