@FXML
  void fromComboBoxAction(ActionEvent event) {
    // fromComboBox.setItems(options);
    /*
    if(fromClicked && toClicked && !lastClicked.equals("from")){
        fromBoxList.setAll(options);
        toBoxList.setAll(options);
        toClicked=false;
        System.out.println("both combo box has been clicked");
    }
    */

    /*System.out.println("now fromBoxList of size "+ fromBoxList.size()+ " will be setAll()");
    fromComboBox.setItems(fromBoxList);
    */

    // fromComboBox=new ComboBox(fromBoxList);
    String s = (String) fromComboBox.getValue();
    c.setFrom(s);

    if (fromComboBox.getValue() == toComboBox.getValue()) {
      toComboBox
          .getSelectionModel()
          .clearSelection(); // to clear the selected option in the other combo box, because the
                             // starting point and destination can't be the same
      c.setTo(null);
      // toComboBox.setButtonCell(null);
      // toComboBox.valueProperty().set(null);
      // toComboBox.getSelectionModel().clearSelection();
    }

    // System.out.println(s.getClass());
    // System.out.println(s);
    System.out.println("from " + s);

    // temp.remove(s);
    /*
    fromClicked=true;
    fromCombo=s;
    lastClicked="from";
    //options.removeAll(s);
    if(fromClicked && !toClicked){
        toBoxList.remove(fromCombo);
        System.out.println("removing "+fromCombo+" from the list and after removing, the size of the toBoxList= "+toBoxList.size());
        toComboBox.setItems(toBoxList);
    }
    */
  }