link from the main menu to other

[sae0203]

how do i link the customer, invoice, inventory, order and product to their individual page?
let's day the name is InventoryWin, CustomerWin, InvoiceWin, OrderWin and ProductWin.

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class MainMenu extends JFrame implements ActionListener
{
public static void main(String args[]){
MainMenu m = new MainMenu();
m.setVisible(true);
}
JLabel mainLabel;
JButton custBtn;
JButton orderBtn;
JButton invoiceBtn;
JButton inventBtn;
JButton productBtn;
JButton exitBtn;
JPanel pane1;
public MainMenu(){
super("Main Menu");
setSize(new Dimension(500, 700));
setDefaultCloseOperation(EXIT_ON_CLOSE);
Container c = this.getContentPane();
c.setLayout(new FlowLayout(FlowLayout.CENTER));
pane1 = new JPanel(new GridLayout(7,1, 30,50));
mainLabel = new JLabel("Main Menu");
mainLabel.setFont(new Font("TimesRoman",Font.BOLD,18));
mainLabel.setForeground(Color.black);
custBtn = new JButton("Customer");
orderBtn = new JButton("Order");
invoiceBtn = new JButton("Invoice");
inventBtn = new JButton("Inventory");
productBtn = new JButton("Product");
exitBtn = new JButton("Exit");

custBtn.addActionListener(this);
orderBtn.addActionListener(this);
invoiceBtn.addActionListener(this);
inventBtn.addActionListener(this);
productBtn.addActionListener(this);
exitBtn.addActionListener(this);

pane1.add(mainLabel);
pane1.add(custBtn);
pane1.add(orderBtn);
pane1.add(invoiceBtn);
pane1.add(inventBtn);
pane1.add(productBtn);
pane1.add(exitBtn);
c.add(pane1);
}
public void actionPerformed(ActionEvent e){
}
}