Opening new forms using jbutton

Question

Hi i'm new to java, and i am currentley building an interface which has three buttons(cars,vans,red car). I have managed to create a class that opens a new window when the car button is clicked. However i am unsure of how to create different windows for when the other buttons are clicked.
Heres my code ive based it on an example i found on here.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import java.awt.Dimension;
import java.awt.GridLayout;
public class Interface extends JPanel implements ActionListener {
JDialog dialog;
public Interface(JFrame f)
dialog = new JDialog(f, "dialog");
dialog.getContentPane().add(new JLabel("hello world", JLabel.CENTER));
dialog.setSize(400,300);
dialog.setLocation(425,200);
public void actionPerformed(ActionEvent e)
if(!dialog.isVisible())
dialog.setVisible(true);
else
dialog.toFront();
public JPanel getPanel()
JPanel panel = new JPanel();
JPanel selectPanel = new JPanel();
JPanel ControlPanel = new JPanel();
selectPanel.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createTitledBorder("Select Piece Type:"),
BorderFactory.createEmptyBorder(5,5,5,5)));
JButton cars = new JButton("Cars");
cars.addActionListener(this);
JButton vans = new JButton("Vans");
JButton redcar = new JButton("Red Car");
selectPanel.add(cars);
selectPanel.add(vans);
selectPanel.add(redcar);
panel.add(selectPanel);
return panel;
public static void main(String[] args)
JFrame f = new JFrame();
Interface ae = new Interface(f);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.getContentPane().add(ae.getPanel(), "North");
f.setSize(400,200);
f.setLocation(200,200);
f.setVisible(true);
Thanks for any help

Answer 1

Thanks for the reply, i am now having trouble adding buttons to the dialog box. This is the code i am using:
dialog = new JDialog(f, "dialog");
        dialog.getContentPane().add(new JLabel("hello world", JLabel.CENTER));
        dialog.setSize(400,300);
        dialog.setLocation(425,200);
        JButton buttonQuestion = new JButton( "Question" );
        dialog.getContentPane().add(buttonQuestion);For some reasson this turns the whole dialog pane into a button. So all i get is a dialog box with question in the middle. What i need is the hello world label to be displayed, with the questin button underneath
Thanks for any help