public void withdraw(int value) {
		if(value < 0) {
			throw new IllegalArgumentException("You can't withdraw a negative number dollars!");
		} else if(value > money) {
			throw new IllegalArgumentException("You don't have enough money to withdraw " +
					value + "dollars!");
		} else {
			notifyPropertyChangeListeners(money, money - value);
			money -= value;
		}
	}