Withdraw method of an ATM

ATM withdraw

   public void withdrawCash() throws BankServiceException {

        //Show user options to withdraw cash
        screen.displayMenuOfWithdrowalAmounts();

        //Read amount from the keypad
        BigDecimal amount = keypad.getAmount();

        //Connect to the bank and check balance
        BigDecimal balance = bankService.getBalance();

        //Check if there is enough money on the account
        if (isTransactionPossible(amount, balance)) {

            //Check if there is enough cash in the dispenser
            if (!cashDispenser.isThereEnoughMoney(amount)) {
                //Display error message
                screen.displayError(INSUFFICIENT_CASH_AVAILABLE);
            } else {

                //Debit amount from user's account
                bankService.debit(amount);

                //Dipenses cash
                cashDispenser.dispenseCash(amount);

                //Bids goodbye
                screen.displayMessage(GOODBYE);

            }
        } else {
            //Display error message
            screen.displayError(AMOUNT_EXCEEDS_BALANCE);
        }
    }