Why is the GUI not showing when i run it

Question

Why is it not showing the container
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
public class Progress extends JFrame {
     private String path;
     private JPanel topLeftPanel;
     private JPanel labelPanel;
     private JTextField pathField;
     public Progress()
          this.setTitle("PROGRESS Message Viewer");
          this.setSize(800, 600);
          Container contentPane = this.getContentPane( );
          // Technique for centering a frame on the screen.
          Dimension frameSize = this.getSize();
          Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
          this.setLocation((screenSize.width - frameSize.width)/2,
                           (screenSize.height - frameSize.height)/2);
          topLeftPanel = new JPanel();
          topLeftPanel.setLayout(new GridLayout(1, 2));
          labelPanel = new JPanel();
          labelPanel.setLayout(new GridLayout(4, 1));
          JLabel l = new JLabel("Please enter the path to log file:  ");
          l.setForeground(Color.black);
          labelPanel.add(l);
          topLeftPanel.add(labelPanel);
          pathField = new JTextField(80);
          ActionListener aListener = new ActionListener() {
               public void actionPerformed(ActionEvent e) {
                    // Retrieve the path.
                    char[] pathFieldText = pathField.getText().toCharArray();
                    path = new String(pathFieldText).trim();
          pathField.addActionListener(aListener);
          contentPane.add(topLeftPanel);
          contentPane.add(pathField);
     public static void main(String []args){
          Progress p = new Progress();
}

Answer 1

Swing related questions should be posted in the Swing forum.
Read the BoderLayout API documentation. If you don't specify a constraint then by default the component is added to the "CENTER". However only a single component can be displayed in any given area of the BorderLayout. So the second add(...) method replaces the first component added.
Read the Swing tutorial on [url http://java.sun.com/docs/books/tutorial/uiswing/layout/visual.html]How to Use Layout Managers for more information.