private String withdrawChecking(Scanner in) throws FileNotFoundException
   {
      System.out.println("Current balance: " + 
      supportedBank.getCheckingBalance(currentCustomer));
      boolean successWithdraw = false;
      while(!successWithdraw)
      {
         System.out.println(
               "Please enter an ammount you like to withdraw: ");
         double withdrawAmount = in.nextDouble();
         if(withdrawAmount > withdrawLimit || withdrawAmount > transactionLimit)
         {
            System.out.println("Please enter an ammount smaller than "
                           + withdrawLimit);
         }
         else if(withdrawAmount > cashOnATM || cashOnATM == 0)
         {
            System.out.println("Sorry, the ATM only has " + cashOnATM);
         }
         else if(withdrawAmount > supportedBank.getCheckingBalance(currentCustomer))
         {
            System.out.println("Isufficient funds, please try a different"
                           + " a different ammount.");
         }
         else
         {
            supportedBank.withdrawChecking(withdrawAmount, currentCustomer);
            System.out.println("Transaction successful, your account balance "
                  + "is: $"
                  + supportedBank.getCheckingBalance(currentCustomer));
            cashOnATM -= withdrawAmount;
            successWithdraw = true;                    
         }
         
                                   
     }
      return "quit";
   }