import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.stage.Stage;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.CheckBox;
import javafx.scene.layout.VBox;

public class App extends Application {
    public static void main(String[] args) {
        launch(args);
    }

    @Override
    public void start(Stage primaryStage) throws Exception {
        CheckBox checkbox1 = new CheckBox("Emese");
        CheckBox checkbox2 = new CheckBox("Béla");
        Button button = new Button("Dupla");

        checkbox1.setSelected(true);
        button.setOnAction(e -> {
            if (checkbox1.isSelected()) {
                System.out.println("Emese ok");
            }
            if (checkbox2.isSelected()) {
                System.out.println("Béla ok");
            }
        });

        VBox vbox = new VBox(10);
        vbox.setPadding(new Insets(10, 10, 10, 10));
        vbox.getChildren().addAll(checkbox1, checkbox2, button);

        Scene scene = new Scene(vbox, 300, 250);
        primaryStage.setScene(scene);

        primaryStage.show();
    }

}