Jak zrobić kolejne okno?

Witam!
Czy moglby mi ktos powiedziec jak dodac kolejne wyskakujace okienko po nacisnieciu jednego z przyciskow?
kontroler:

package Kaczuszka;
import javafx.scene.input.MouseEvent;

import java.io.IOException;
import java.net.URL;
import java.util.ResourceBundle;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Label;
import javafx.scene.control.Button;
import javafx.scene.text.Font;
/**
 *
 * @author Kamil
 */
public class FXMLDocumentController implements Initializable {
    
    @FXML
    private Label label;
     @FXML
    private Button kalendarz, terminarz, plan;
    @FXML
    private void handleButtonAction(ActionEvent event) throws IOException {
   
    }
      @FXML

    private void ogarnij(ActionEvent event) {
        System.out.println("You clicked me!");
       
    }
    // eventy Entered i Exit
@FXML 
public void najedz(MouseEvent e)
{
    kalendarz.setFont(Font.font ("Verdana", 15));
}
@FXML
public void zjedz(MouseEvent e)
{
    kalendarz.setFont(Font.font ("Verdana", 11));
}
@FXML 
public void najedz2(MouseEvent e)
{
    terminarz.setFont(Font.font ("Verdana", 15));
}
@FXML
public void zjedz2(MouseEvent e)
{
    terminarz.setFont(Font.font ("Verdana", 11));
}
@FXML 
public void najedz3(MouseEvent e)
{
    plan.setFont(Font.font ("Verdana", 15));
}
@FXML
public void zjedz3(MouseEvent e)
{
    plan.setFont(Font.font ("Verdana", 11));
}
 
    @Override
    public void initialize(URL url, ResourceBundle rb) {
        // TODO
    }    
    
}

package Kaczuszka;

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;

/**
 *
 * @author Kamil
 */
public class Kaczuszka extends Application {
    
    @Override
    public void start(Stage stage) throws Exception {
        Parent root = FXMLLoader.load(getClass().getResource("FXMLDocument.fxml"));
        
        Scene scene = new Scene(root);
        
        stage.setScene(scene);
        stage.setTitle("Terminator");
        stage.show();
        
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        launch(args);
    }
    
}