Hi sorry if this has already been posted but my code doesn't work as it should. I am new to java programming and would like someone to point me in the right direction on how I could change to desired panels by pressing a button. In my code it only shows the first panel and when I press the button to show the next panel it gives me Wrong parent for CardLayout error. Also this is my first question, I hope you are clear what I'm trying to ask.

// **class Containing the cardLayout**

import java.awt.CardLayout;
import java.awt.Container;
import java.util.HashMap;

import javax.swing.JFrame;
import javax.swing.JPanel;
public class Frame extends JFrame{

    IDandPassword idandPasswords = new IDandPassword();
    JPanel login = new LoginPage(idandPasswords.getLoginInfo());
    JPanel newUser = new NewUser();
    Encryption enc = new Encryption();
    Decryption dec = new Decryption();
    CardLayout cl = new CardLayout();
    Container panel = new Container();
    
    
    
    
    void setGui() {
        
        
        
        this.setSize(420,420);
        this.setVisible(true);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setLocationRelativeTo(null);
        this.setResizable(false);
        this.setContentPane(panel);
        System.out.println("Frame");
        
        panel.setLayout(cl);
        
        panel.add(login,"1");
        panel.add(newUser,"2");
        panel.add(enc,"3");
        panel.add(dec,"4");
        
        
        
    }

// **Class containing the 1st panel to show

import java.awt.Color;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.HashMap;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;



public class LoginPage extends JPanel implements ActionListener{

    
    JButton loginButton = new JButton("Login");
    JButton resetButton = new JButton("Reset");
    JButton newUserButton = new JButton("Add User");
    JTextField UserIdField = new JTextField();
    JPasswordField UserPasswordField = new JPasswordField();
    JLabel userIdLabel = new JLabel("User ID");
    JLabel userPasswordLabel = new JLabel("Password");
    JLabel messageLabel = new JLabel();
    
    
    
    
    
    
    HashMap <String,String> logininfo = new HashMap<String,String>();
    
    LoginPage(HashMap<String,String> loginInfoOriginal) {
        
        System.out.println("Login page constructor");

        this.setSize(420,420);
        this.setLayout(null);
        this.setFocusable(true);
        
        logininfo = loginInfoOriginal;
        
        userIdLabel.setBounds(50,100,75,25);
        userPasswordLabel.setBounds(50,150,75,25);
        
        messageLabel.setBounds(125,303,250,35);
        messageLabel.setFont(new Font(null,Font.BOLD,25));
        
        
        UserIdField.setBounds(125,100,200,25);
        UserPasswordField.setBounds(125,150,200,25);
        
        loginButton.setBounds(125,200,100,25);
        loginButton.setFocusable(false);
        loginButton.addActionListener(this);
        
        resetButton.setBounds(225,200,100,25);
        resetButton.setFocusable(false);
        resetButton.addActionListener(this);
        
        newUserButton.setBounds(125,250,100,25);
        newUserButton.setFocusable(false);
        newUserButton.addActionListener(this);
        
        this.add(userIdLabel);
        this.add(userPasswordLabel);
        this.add(messageLabel);
        this.add(UserIdField);
        this.add(UserPasswordField);
        this.add(loginButton);
        this.add(resetButton);
        this.add(newUserButton);
        
        
    }
    
    
    @Override
    public void actionPerformed(ActionEvent e) {
        
        if(e.getSource() == resetButton) {
            UserIdField.setText("");
            UserPasswordField.setText("");
            messageLabel.setText("");
            
        }
        
        if(e.getSource() == loginButton) {
            
            String userId = UserIdField.getText();
            String password = String.valueOf(UserPasswordField.getPassword());
            
            if(logininfo.containsKey(userId)) {
                if(logininfo.get(userId).equals(password)) {
                    messageLabel.setForeground(Color.green);
                    messageLabel.setText("Login Successful");
                    
                    
                    
                }
                else {
                    messageLabel.setForeground(Color.red);
                    messageLabel.setText("Incorrect Password");
                }
            }else {
                messageLabel.setForeground(Color.red);
                messageLabel.setText("Invalid Username");
            }
            
        }
        if(e.getSource() == newUserButton) {
            
            Frame f= new Frame();
            f.cl.show(f.getContentPane(), "2");
            
            
        }
        
    }

}


//**class Containing 2nd panel to show

import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class NewUser extends JPanel implements ActionListener{

    JButton addButton = new JButton("Add");
    JButton resetButton = new JButton("Reset");
    JTextField newUserIdField = new JTextField();
    JTextField newUserPasswordField = new JTextField();
    JLabel newUserIdLabel = new JLabel("New User ID");
    JLabel newuserPasswordLabel = new JLabel("New Password");
    JLabel messageLabel = new JLabel();
    JLabel titleLabel = new JLabel("Add a new User");
    JButton backButton = new JButton("Back");
    
     NewUser() {
         
        
        this.setSize(420,420);
        this.setLayout(null);
        this.setFocusable(true);
        
        newUserIdLabel.setBounds(22,100,75,25);
        newuserPasswordLabel.setBounds(22,150,89,25);
        
        messageLabel.setBounds(125,250,250,35);
        messageLabel.setFont(new Font(null,Font.BOLD,25));
        titleLabel.setFont(new Font("Tahoma", Font.BOLD, 14));
        
        titleLabel.setBounds(125,43,108,35);
        
        newUserIdField.setBounds(125,100,200,25);
        newUserPasswordField.setBounds(125,150,200,25);
        
        addButton.setBounds(125,200,100,25);
        addButton.setFocusable(false);
        addButton.addActionListener(this);
        
        resetButton.setBounds(225,200,100,25);
        resetButton.setFocusable(false);
        resetButton.addActionListener(this);
        
        backButton.setBounds(263,302,100,25);
        backButton.addActionListener(this);
        backButton.setFocusable(false);
        
        this.add(newUserIdLabel);
        this.add(newuserPasswordLabel);
        this.add(messageLabel);
        this.add(newUserIdField);
        this.add(newUserPasswordField);
        this.add(addButton);
        this.add(resetButton);
        this.add(addButton);
        this.add(titleLabel);
        this.add(backButton);
        
    }
     public void addUser() {
         IDandPassword idandPasswords = new IDandPassword();
         idandPasswords.setLoginInfo(newUserIdField.getText(),newUserPasswordField.getText());
         
     }
     

    @Override
    public void actionPerformed(ActionEvent e) {
        
        if(e.getSource() == backButton) {
            
            IDandPassword idandPasswords = new IDandPassword();
            Frame frame =new Frame();
            frame.setContentPane(new LoginPage(idandPasswords.getLoginInfo()));
        }
        if(e.getSource() == addButton) {
            IDandPassword idandPasswords = new IDandPassword();
            
            if(idandPasswords.logininfo.containsKey(newUserIdField.getText())) {
                System.out.println("User already exists");
            }
            else {
                
            if(newUserIdField.getText() != "" && newUserPasswordField.getText() != "") {
                addUser();
                System.out.println("User added");
            }
            
            }
            
        }
        
        
    }

}



// **Main Class**

public class Main {
    
    

    public static void main(String[] args) {
        
        
        
        Frame f=new Frame();
        f.setGui();
        
        
        
        
        
        
    }

}