@Override
	public void actionPerformed(ActionEvent e) {
		Object source = e.getSource();
		if (source instanceof Vehicle) {
			Vehicle vehicle = (Vehicle) source;
			if (e.getActionCommand().equals(Constants.OPERATION_UPDATE)) {
				if (this.vehicle == vehicle) {
					updateVehicle(vehicle);
				}
			}
		} else if (source instanceof Location) {
			Location location = (Location) source;
			if (e.getActionCommand().equals(Constants.OPERATION_CREATE)) {
				if (comboBoxModel.getIndexOf(location) == -1) {
					comboBoxModel.addElement(location);
				}
			} else if (e.getActionCommand().equals(Constants.OPERATION_DELETE)) {
				comboBoxModel.removeElement(location);
			}
		}
	}