if (userAction = withdraw)
{
  double balance = Account.getBalance();
  System.out.println ("Bank balance is " + balance);
  double newbalance = balance - 100;      // the user withdraw $100
  Account.setBalance (newBalance);        // the balance must be updated to the new balance
  balance = Account.getBalance();         // get the new balance
  System.out.println ("Your new balance is " + balance);
}