Sorry bug you guys but can somebody help me?

[babs115]

I created buttons in the menu,no syntax error but cardholder is not visible. Please help!!!

import java.awt.*;
import javax.swing.*;
import javax.swing.table.*;
import java.awt.event.*;
 
public class MainMenu extends JFrame implements ActionListener
{
    private DefaultTableModel model;
    private JTable table;
    private JScrollPane scroll;
    private JPanel panel;
 
    private CardLayout cardLayout;
    private JPanel cardHolder;
 
    private GridBagLayout gridBag;
    private GridBagConstraints c;
 
    static JPanel mainMenuCard, manageCustomerCard,manageSaleCard,manageSaleBookCard,makeOrderCard,viewCartCard;
    static JLabel titleLbl;
    static JButton manageCustomerBtn,manageSaleBtn,manageSaleBookBtn,makeOrderBtn,viewCartBtn,exitBtn;
 
 
    public MainMenu()
    {
        super("MainMenu");
        setSize(800,800);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        createGUI();
        setVisible(true);
 
        cardLayout = new CardLayout();
        cardHolder = new JPanel();
        cardHolder.setLayout(cardLayout);
 
        //createMainMenuCard();
        titleLbl=new JLabel("MAIN MENU");
        manageCustomerBtn=new JButton("Manage Customer");
        manageSaleBtn=new JButton("Manage Sale");
        manageSaleBookBtn=new JButton("Manage Sale Book");
        makeOrderBtn=new JButton("Make Order");
        viewCartBtn=new JButton("View Cart");
        exitBtn=new JButton("Exit");
 
        cardHolder.add(mainMenuCard,"mainMenuCard");
        cardHolder.add(manageCustomerCard,"manageCustomerCard");
        cardHolder.add(manageSaleCard,"manageSaleCard");
        cardHolder.add(manageSaleBookCard,"manageSaleBookCard");
        cardHolder.add(makeOrderCard,"makeOrderCard");
        cardHolder.add(viewCartCard,"viewCartCard");
 
        manageCustomerBtn.addActionListener(this);
        manageSaleBtn.addActionListener(this);
        manageSaleBookBtn.addActionListener(this);
        makeOrderBtn.addActionListener(this);
        viewCartBtn.addActionListener(this);
        exitBtn.addActionListener(this);
 
        c.gridwidth=1;
        c.gridheight=1;
        c.gridheight=1;
        c.gridheight=1;
        c.gridheight=1;
        c.gridheight=1;
        c.weightx=0;
        c.weighty=0;
        c.weighty=0;
        c.weighty=0;
        c.weighty=0;
        c.weighty=0;
        c.fill=GridBagConstraints.HORIZONTAL;
 
        addComponent(titleLbl,0,0,0,0,0,0);
        addComponent(manageCustomerBtn,0,1,0,0,0,0);
        addComponent(manageSaleBtn,0,2,0,0,0,0);
        addComponent(manageSaleBookBtn,0,3,0,0,0,0);
        addComponent(makeOrderBtn,0,4,0,0,0,0);
        addComponent(viewCartBtn,0,5,0,0,0,0);
        addComponent(exitBtn,0,6,0,0,0,0);
 
        add(cardHolder);
        setVisible(true);
    }
 
     public void addComponent(Component comp,int gx,int gy,int t,int l,int b,int r)
    {
        c.gridx=gx;
        c.gridy=gy;
        c.insets=new Insets(t,l,b,r);
        gridBag.setConstraints(comp,c);
        add(comp);
    }
 
 
 
    public void createGUI()
    {
        model=new DefaultTableModel();
 
        int rows = 5,cols = 5;
        model=new DefaultTableModel(rows,cols);
 
       // Object[] colNames={"Customer Id", "Customer Name","Customer Phone", "Customer Email"};
       // model = new DefaultTableModel(null,colNames);
 
          Object[][] data={};//{,"",""},{,"",""}};
          Object[] colNames={};//{"","",""};
        model = new DefaultTableModel(data,colNames)
        {
            public boolean isCellEditable(int row,int col)
            {
                return false;
            }
        };
 
        table=new JTable(model)
        {
            boolean[] cellEditables={false,true,true};
            public boolean isCellEditable(int row,int col)
            {
                return cellEditables[col];
            }            
        };
 
        table.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
 
        scroll=new JScrollPane(table);
        scroll.setPreferredSize(new Dimension(350,250));
        panel=new JPanel();
        panel.add(scroll);
        add(panel);
    }
 
    public static void main(String[] args)
    {
        new MainMenu();
    }
 
 
    public void actionPerformed(ActionEvent evt)
    {
 
    }
 
}
 
 

[Rangan]

static JPanel mainMenuCard, manageCustomerCard,manageSaleCard,manageSaleBookCard,makeOrderCard,viewCartCard;

You didnt create new object for those component then add into cardHolder component.