public static AccountHolder DemandAuthentication(IDataAccessLayer dal) { AccountHolder ach = null; bool first = true; while (ach == null) { if (first) { Console.WriteLine("Hello and welcome to our bank software."); first = false; } else { Console.WriteLine("Incorrect Username/Password. Please try again."); } Console.WriteLine("Please enter your username and password:"******"Username:"******"Password:"); string password = Console.ReadLine(); ach = dal.AttemptLogin(username, password); } return ach; }