public void showSkiPassInfo() {
        if (skiPassCard == null) {
            System.out.println("\nYou don't have a ski-pass card!");
        } else {
            System.out.println("\nSki-pass info:");
            System.out.println("ID\t" + skiPassCard.getID());
            System.out.println("Card type\t" + skiPassCard.getCardType());
            System.out.println("Activated on\t" + skiPassCard.getActivationDate());
            System.out.println("Expired on\t" + skiPassCard.getExpirationDate());
            if (skiPassCard instanceof LimitedSkiPass) {
                System.out.println("Passages left\t"
                        + ((LimitedSkiPass) skiPassCard).getNumPassages());
            }
        }
    }