Mine

import java.awt.Dimension;import java.awt.event.*;import java.awt.*;import javax.swing.JFrame;import javax.swing.UIManager;import javax.swing.JPanel;import javax.swing.*;public class Test implements ActionListener {		public Component createComponents() {		JPanel panel = new JPanel(new GridLayout(0,1));		//panel.setBackground(new Color(0.0f, 0.5f, 0.0f));		return panel;	}		public void actionPerformed(ActionEvent e) {		  	}		 private static void initLookAndFeel() {		 try {				UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());			}catch(Exception e)			{				System.out.println("Look and feel failed: " + e);			} 	 }	 private static void createAndShowGUI() {					 	initLookAndFeel();		 	Dimension dim = new Dimension(640,480);					 	JFrame.setDefaultLookAndFeelDecorated(true);		 			 	JFrame frame = new JFrame("Hello!");		 	frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);					 	frame.setSize(dim);			frame.setMinimumSize(dim);			frame.setMaximumSize(dim);									Test myTest = new Test();			Component contents = myTest.createComponents();			frame.getContentPane().add(contents,BorderLayout.CENTER);						frame.setBackground(new Color(0.0f, 0.5f, 0.0f));									frame.pack();			frame.setVisible(true);		}	 	 	 /**	 * @param args	 */	public static void main(String[] args) {	    javax.swing.SwingUtilities.invokeLater(new Runnable() {            public void run() {                createAndShowGUI();            }        });			}}