Buttons opens in Central Panel ?

Question

Hey Dudes ! I`ve created 3 panels(left, right and center). Additionally, 3 JButtons in left panel.
Hence, I would like those buttons to open the classes that I`ve created. I`m already able to open it in a new window. BUT, I would want those classes to open in the central panel.
Please Help !

Answer 1

public class NO2SCREEN extends javax.swing.JFrame {
/** Creates new form NO2SCREEN */
public NO2SCREEN() {
initComponents();
private void initComponents() {
left = new javax.swing.JPanel();
employee = new javax.swing.JButton();
account = new javax.swing.JButton();
landlord = new javax.swing.JButton();
center = new javax.swing.JPanel();
right = new javax.swing.JPanel();
getContentPane().setLayout(new java.awt.GridLayout(0, 3, 20, 20));
addWindowListener(new java.awt.event.WindowAdapter() {
public void windowClosing(java.awt.event.WindowEvent evt) {
exitForm(evt);
left.setLayout(new java.awt.GridLayout(3, 0));
employee.setForeground(java.awt.Color.red);
employee.setFont(new java.awt.Font("Verdana", 1, 18));
employee.setText("EMPLOYEE");
employee.setBackground(java.awt.Color.lightGray);
employee.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
employeeActionPerformed(evt);
left.add(employee);
account.setForeground(java.awt.Color.red);
account.setFont(new java.awt.Font("Verdana", 1, 18));
account.setText("ACCOUNT");
account.setBackground(java.awt.Color.lightGray);
account.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
accountActionPerformed(evt);
left.add(account);
landlord.setForeground(java.awt.Color.red);
landlord.setFont(new java.awt.Font("Verdana", 1, 18));
landlord.setText("LANDLORD");
landlord.setBackground(java.awt.Color.lightGray);
landlord.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
landlordActionPerformed(evt);
left.add(landlord);
getContentPane().add(left);
getContentPane().add(center);
getContentPane().add(right);
pack();
private void landlordActionPerformed(java.awt.event.ActionEvent evt) {
landlord ld = new landlord();
ld.show();
private void accountActionPerformed(java.awt.event.ActionEvent evt) {
account ac = new account();
ac.show();
private void employeeActionPerformed(java.awt.event.ActionEvent evt) {
employee ee = new employee();
ee.show();
/** Exit the Application */
private void exitForm(java.awt.event.WindowEvent evt) {
System.exit(0);
* @param args the command line arguments
public static void main(String args[]) {
new NO2SCREEN().show();
// Variables declaration
private javax.swing.JPanel left;
private javax.swing.JButton employee;
private javax.swing.JButton account;
private javax.swing.JButton landlord;
private javax.swing.JPanel center;
private javax.swing.JPanel right;
// End of variables declaration
}