public void Transfer(decimal amt, BankAccount one, BankAccount two)
        {
            if(one.IsOpen && two.IsOpen && amt <= one.Ammount)
            {
                two.Ammount += amt;
                one.Ammount -= amt;

            }
        }
 public void Transfer(BankAccount destination, BankAccount start, decimal amount) {
     //open? enough $$ in account?
     if (destination.IsOpen && start.IsOpen) {
         if (start.Amount >= amount) {
             start.Amount -= amount;
             destination.Amount += amount;
         }
         else {
             Console.WriteLine("Transaction unsuccessful! Not enough $$ in account!");
         }
     }
     else {
         Console.WriteLine("Transaction unsuccessful! One of the accounts is closed!");
     }
 }