public Object getValueAt(int row, int col) {
		Account account = accounts.getBusinessObjects().get(row);
		if (col == 0) {
			return account;
		}
		if (col == 1) {
			if(account==null) return null;
			if(account.getType().isInverted())
				return account.getSaldo().negate();
			else return account.getSaldo();
			// TODO: use this isInverted() switch to call negate() in other places
		}
		return null;
	}