system login window java compiles but doesn't run

Question

Hey so I am working on a system login window for my computer science course. The professor wants a system login window with a checkbox to mark if username is case sensitive and another check box to show the password. So far my code compiles but it will not run and I cant figure out why, my code isn't finished but Im unsure where to go from here. When I compile I get the following

 ----jGRASP exec: java Win_SystemLogin
 Exception in thread "main" java.lang.NullPointerException
    at java.awt.Container.addImpl(Container.java:1097)
    at java.awt.Container.add(Container.java:417)
    at Win_SystemLogin.CreateComponents(Win_SystemLogin.java:71)
    at Win_SystemLogin.<init>(Win_SystemLogin.java:37)
    at Win_SystemLogin.main(Win_SystemLogin.java:100)

  ----jGRASP wedge2: exit code for process is 1.

Here is my code

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;

public class Win_SystemLogin extends JFrame
{
   final String SYS_USERNAME = "Fernando";
   final String SYS_PASSWORD = "Zavala";

   int WIN_WIDTH = 400; 
   int WIN_HEIGHT = 400;

   private JPanel panelN;
   private JPanel panelS;
   private JPanel panelE;
   private JPanel panelW;
   private JPanel panelC;

   private JLabel       attemptsLabel;
   private JTextField   attemptsTextField;
   private JLabel       userNameLabel;
   private JTextField   userNameJTextField;
   private JLabel       passwordLabel;
   private JTextField   passwordJTextField;
   private JButton      loginButton;
   private JButton      exitButton;
   private JCheckBox    caseSensitiveCheckBox;

public Win_SystemLogin()
{
   setTitle("System Login");
   setSize(WIN_WIDTH, WIN_HEIGHT);
   setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   setLayout(new BorderLayout() );


   CreateComponents();
   add (panelN,BorderLayout.NORTH);
   add (panelS,BorderLayout.SOUTH);
   add (panelE,BorderLayout.EAST);
   add (panelW,BorderLayout.WEST);
   add (panelC,BorderLayout.CENTER);
   setVisible(true);

   loginButton.addActionListener(new ButtonListener());
   exitButton.addActionListener(new ButtonListener());
}
private void CreateComponents()
{
userNameLabel = new JLabel("Username");
passwordLabel = new JLabel("Password");
userNameJTextField = new JTextField();
passwordJTextField = new JTextField();
attemptsLabel = new JLabel("Attempts");
attemptsTextField = new JTextField(10);
loginButton = new JButton("Login");
exitButton = new JButton("Exit");

JPanel panelN = new JPanel();
JPanel panelE = new JPanel();
JPanel panelS = new JPanel();
JPanel panelW = new JPanel();
JPanel panelC = new JPanel();

panelC.add(userNameLabel);
panelC.add(userNameJTextField);
panelC.add(passwordLabel);
panelC.add(passwordJTextField);
panelE.add(attemptsLabel);
panelE.add(attemptsTextField);
panelE.add(caseSensitiveCheckBox);
panelS.add(loginButton);
panelS.add(exitButton);

pack();
setVisible(true);


}
private class ButtonListener implements ActionListener
{
   public void actionPerformed(ActionEvent e)
   {
   String actionCmd = e.getActionCommand();

   if (actionCmd.equals("Login"))
   {

   JOptionPane.showMessageDialog(null,"Welcome" );
   }
   else if(actionCmd.equals("Exit"))
   {
   System.exit(0);
   }

   }
}
public static void main(String args[])
{
   new Win_SystemLogin();
}
}