Problem with JComboBox and Jlist

[java_fun2007]

I want the program to add array in the combobox according to my selectedindex of the radiobuttons.

import java.awt.*;
import javax.swing.JFrame;
import java.awt.event.*;
import javax.swing.*;

public class AnimalType extends JFrame implements ActionListener, ItemListener
{	private JRadioButton cat;
	private JRadioButton dog;
	private JRadioButton bird;
	private ButtonGroup animals;
	private JComboBox Zoo;
	private String catnames[]= {"Tom", "Meow", "Pete"};
	private String dognames[] =  {"bobby", "Roy", "Lassie"};
	private String birdnames[] =  {"kiko", "tweety", "birdy"};
	private DefaultComboBoxModel cmb;
	
	public AnimalType()
	{	super("zoo!");
	setLayout( new FlowLayout() );
	cat = new JRadioButton("cat",true);
		dog = new JRadioButton("dog",false);
		bird = new JRadioButton("bird",false);
		animals = new ButtonGroup();
		animals.add(cat);
		animals.add(dog);
		animals.add(bird);
		add(cat);
		add(dog);
		add(bird);
	
	

		
	cmb = new DefaultComboBoxModel(catnames);
	Zoo = new JComboBox(cmb);
	add(Zoo);
	Zoo.addItemListener(this);
		cat.addItemListener(this);
		dog.addItemListener(this);
		bird.addItemListener(this);
			bird.addActionListener(this);
	}//end const.
	public void actionPerformed(ActionEvent evt)
	{
		

		if (bird.isSelected())
		{cmb.removeAllElements();
	 cmb.addElement(birdnames);
		}
	}
	
	public void itemStateChanged(ItemEvent evt)
	{ 
	Object source = evt.getSource();
	if (cat.isSelected()){cmb.removeAllElements();
	 //cmb.addElement(catnames);
	 }

	else if (dog.isSelected()){
if (cmb != null)
{cmb.removeAllElements();
}

cmb.addElement(dognames); 
	 	}
	 
	else if (bird.isSelected()){cmb.removeAllElements();
	// cmb.addElement(birdnames);	
	}

	}
	public static void main(String[] args) {
      AnimalType test = new AnimalType();
      test.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   	test.setSize(400,400);
    test.setVisible(true);
    }
	}//end class

[hardwired]

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class AnimalTypeRx extends JFrame implements ActionListener,
                                                    ItemListener
{
    private JRadioButton cat;
    private JRadioButton dog;
    private JRadioButton bird;
    private JComboBox Zoo;
    private String[] catNames =
    {
        "Tom", "Meow", "Pete"
    };
    private String[] dogNames =
    {
        "bobby", "Roy", "Lassie"
    };
    private String[] birdNames =
    {
        "kiko", "tweety", "birdy"
    };
    private DefaultComboBoxModel cmb;

    public AnimalTypeRx()
    {
        super("zoo!");
        setLayout( new FlowLayout() );
        cat = new JRadioButton("cat",true);
        dog = new JRadioButton("dog",false);
        bird = new JRadioButton("bird",false);
        ButtonGroup animals = new ButtonGroup();
        animals.add(cat);
        animals.add(dog);
        animals.add(bird);
        add(cat);
        add(dog);
        add(bird);

        cmb = new DefaultComboBoxModel(catNames);
        Zoo = new JComboBox(cmb);
        Dimension d = Zoo.getPreferredSize();
        System.out.printf("d = [%d, %d]%n", d.width, d.height);
        d.width = 85;
        Zoo.setPreferredSize(d);
        add(Zoo);

//        Zoo.addActionListener(this);
        // This is all we need.
        cat.addActionListener(this);
        dog.addActionListener(this);
        bird.addActionListener(this);

        // Just to see what this can do.
        cat.addItemListener(this);
        dog.addItemListener(this);
        bird.addItemListener(this);
    }

    public void actionPerformed(ActionEvent evt)
    {
        JRadioButton rb = (JRadioButton)evt.getSource();
        String[] items = null;
        if(rb == cat)
            items = catNames;
        if(rb == dog)
            items = dogNames;
        if(rb == bird)
            items = birdNames;
        resetModelData(items);
    }

    private void resetModelData(String[] items)
    {
        cmb.removeAllElements();
        // The view component listens to the model and
        // updates itself when changes are made to the model.
        for(int i = 0; i < items.length; i++)
        {
            cmb.addElement(items[i]);
        }
    }

    public void itemStateChanged(ItemEvent evt)
    {
        if(evt.getStateChange() == ItemEvent.SELECTED)
        {
            JRadioButton rb = (JRadioButton)evt.getSource();
            if (rb == cat)
            {
                System.out.println("cat selected");
            }
            else if (rb == dog)
            {
                System.out.println("dog selected");
            }
            else if (rb == bird)
            {
                System.out.println("bird selected");
            }
        }
    }

    public static void main(String[] args)
    {
        AnimalTypeRx test = new AnimalTypeRx();
        test.setDefaultCloseOperation(EXIT_ON_CLOSE);
        test.setSize(400,400);
        test.setVisible(true);
    }
}

[java_fun2007]

thanks hardwired now it's working fine.