public Object getValueAt(int row, int col) {
		Booking booking = transaction.getBusinessObjects().get(row);
		if (booking.isDebit()) {
			if (col == 0) {
				return booking.getAccount();
			}
			if (col == 2) {
				return booking.getAmount();
			}
			return null;
		}// else credit
		if (col == 1) {
			return booking.getAccount();
		}
		if (col == 3) {
			return booking.getAmount();
		}
		return null;
	}