Please tell me what is the problem with this code

Question

Hai,
Iam new to Swings. can any one tell what is the problem with this code. I cant see those controls on the frame. please give me the suggestions.
I got the frame ,but the controls are not.
this is the code:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class ex2 extends JFrame
JButton b1;
JLabel l1,l2;
JPanel p1,p2;
JTextField tf1;
JPasswordField tf2;
public ex2()
setDefaultCloseOperation(EXIT_ON_CLOSE);
setTitle("Another example");
setSize(500,500);
setVisible(true);
b1=new JButton(" ok ");
p1=new JPanel();
p1.setLayout(new GridLayout(2,2));
p2=new JPanel();
p2.setLayout(new BorderLayout());
l1=new JLabel("Name :");
l2=new JLabel("Password:");
tf1=new JTextField(15);
tf2=new JPasswordField(15);
Container con=getContentPane();
con.add(p1);
con.add(p2);
public static void createAndShowGUI()
ex2.setDefaultLookAndFeelDecorated(true);
public static void main(String ar[])
createAndShowGUI();
new ex2();
}

Answer 1

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class ex2 extends JFrame
    JButton b1;
    JLabel l1,l2;
    JPanel p1,p2;
    JTextField tf1;
    JPasswordField tf2;
    public ex2()
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setTitle("Another example");
        b1=new JButton(" ok ");
        p1=new JPanel();
        p1.add(b1);
        p2=new JPanel();
        p2.setLayout(new GridLayout(2,2));
        l1=new JLabel("Name :");
        l2=new JLabel("Password:");
        tf1=new JTextField(15);
        tf2=new JPasswordField(15);
        p2.add(l1);
        p2.add(tf1);
        p2.add(l2);
        p2.add(tf2);
        Container con=getContentPane();
        con.add(p1, BorderLayout.NORTH);
        con.add(p2, BorderLayout.CENTER);
        pack();
        setVisible(true);
    public static void createAndShowGUI()
        ex2.setDefaultLookAndFeelDecorated(true);
    public static void main(String ar[])
        createAndShowGUI();
        new ex2();
}