JButton ok = new JButton ( "OK" );
ok.setForeground ( white );
ok.setBackground( green );
ok.setFont( new Font( "Dialog" , Font. BOLD, 12 ));
ok.addActionListener( new ActionListener()
                         {
                         /**
                         * Invoked when OK button clicked.
                         */
                         public void actionPerformed ( ActionEvent e )
                            {
                            doSomething();
                            }
                         }
                    );
contentPane.add( ok ,
                 new GridBagConstraints ( 0, 13, 1, 1,
                                          0.0, 0.0,
                                          GridBagConstraints.NORTHEAST, GridBagConstraints.NONE,
                                          new Insets( 20, 8, 4, 4) ,
                                          0, 0 ) );