Separte GUI and application code

Question

Below is my code to separate GUI and application code. When i try to execute the code i get message applet not initiated. Can any one point what mistake i am doing in the code.
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
class ColorAction extends AbstractAction
     public ColorAction(String name, Icon icon,Color c, Component comp)
          putValue(Action.NAME, name);
          putValue(Action.SMALL_ICON,icon);
          putValue("Color",c);
          target = comp;
     public void actionPerformed(ActionEvent evt)
          Color c = (Color)getValue("Color");
          target.setBackground(c);
          target.repaint();
     private Component target;
class ActionButton extends JButton
     public ActionButton(Action a)
          setText((String)a.getValue(Action.NAME));
          Icon icon = (Icon)a.getValue(Action.SMALL_ICON);
          if(icon != null)
               setIcon(icon);
          addActionListener(a);
public class SepGUI extends JApplet
     public void init()
          JPanel panel = new JPanel();
          Action blueAction = new ColorAction("Blue",new ImageIcon("a.gif"),Color.blue,panel);
          Action yellowAction = new ColorAction("Yellow",new ImageIcon("a.gif"),Color.yellow,panel);
          Action redAction = new ColorAction("Red",new ImageIcon("a.gif"),Color.red,panel);
          panel.add(new ActionButton(yellowAction));
          panel.add(new ActionButton(blueAction));
          panel.add(new ActionButton(redAction));
          Container contentPane = getContentPane();
          contentPane.add(panel);
}

Answer 1

public class SepGUI extends JApplet
  public void init()
    JPanel panel = new JPanel();
    try
      Action blueAction = new ColorAction("Blue",new ImageIcon(new java.net.URL (getCodeBase(),"a.gif")),Color.blue,panel);
      Action yellowAction = new ColorAction("Yellow",new ImageIcon(new java.net.URL (getCodeBase(),"a.gif")),Color.yellow,panel);
      Action redAction = new ColorAction("Red",new ImageIcon(new java.net.URL (getCodeBase(),"a.gif")),Color.red,panel);
      panel.add(new ActionButton(yellowAction));
      panel.add(new ActionButton(blueAction));
      panel.add(new ActionButton(redAction));
    catch(Exception e){}
    Container contentPane = getContentPane();
    contentPane.add(panel);
}