Adding my own object to a Container...not working.

Okay, so this is my first post. Hello all! :D
I am writing a program for my dad to use at his cabinet making business. The program is being designed to create the dimensions for cabinet doors. My problem is, on the second display I have a JComboBox I want to show up. I created a new class to use to instantiate this box, and now it doesn't show up because I can't add it to my Container. I tried changing my ComboBox.java to extend JComboBox so it would be considered a Component, buuuut that didn't work so well for me. So instead, the ComboBox.java is considered an object I made and not a component, therefore my container will not allow me to add it so it shows up. Any ideas and/or solutions would be wonderful! Thank You!

PS. My ComboBox class compiles with no errors, the only error on my GUI class is that I can't add my own object.

here is the portion of my GUI that I am trying to add the box to:

Code :

/*** ComboBox Being Created ***/
 
   public ComboBox createComboBox()
   {
   	boxPanel = new JPanel();
		boxDoorType = new ComboBox( createDoubleDoorDisplay(),
											 createSingleDoorOptions(),
											 createDoubleDoorOptions() );
 
		boxPanel.add( boxDoorType );
		c.add( boxPanel );
		return boxDoorType;
   }

And here is my ComboBox class:

Code :

import java.util.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.Font.*;
import java.awt.Dimension.*;
 
 
 
public class ComboBox implements ItemListener
{
	/*** Class Variables ***/
 
	private String[] boxOptions  = new String[ 3 ];
	private JPanel[] boxDisplays = new JPanel[ 3 ];
 
	private JComboBox cmbxDoorType;
 
	private JPanel createDoubleDoorDisplay;
	private JPanel createSingleDoorOptions;
	private JPanel createDoubleDoorOptions;
 
	/*** Constructor ***/
	public ComboBox( JPanel pCreateDoubleDoorDisplay,
						  JPanel pCreateSingleDoorOptions,
						  JPanel pCreateDoubleDoorOptions,
						  String pBoxOption1,
						  String pBoxOption2,
						  String pBoxOption3)
	{
 
		createDoubleDoorDisplay = pCreateDoubleDoorDisplay;
		createDoubleDoorDisplay.setVisible( false );
 
		createSingleDoorOptions = pCreateSingleDoorOptions;
		createSingleDoorOptions.setVisible( false );
 
		createDoubleDoorOptions = pCreateDoubleDoorOptions;
		createDoubleDoorOptions.setVisible( false );
	}
 
	/*** Accessors ***/
 
	public String[] getBoxOptions()
	{
		return boxOptions;
	}
 
	public JPanel[] getBoxDisplays()
	{
		return boxDisplays;
	}
 
	/*** Mutators/Transformers ***/
 
	public void setBoxOptions( String pBoxOptions, int pInt )
	{
		boxOptions[ pInt ] = pBoxOptions;
	}
 
	public void setBoxDisplays( JPanel pBoxDisplays, int pInt )
	{
		boxDisplays[ pInt ] = pBoxDisplays;
		pBoxDisplays.setVisible( true );
	}
 
	public JComboBox createComboBox( String pBoxOption1,
						  						String pBoxOption2,
						  						String pBoxOption3 )
   {
   	setBoxOptions( pBoxOption1, 0 );
   	setBoxOptions( pBoxOption2, 1 );
   	setBoxOptions( pBoxOption3, 2 );
 
 
		cmbxDoorType = new JComboBox( boxOptions );						                 // JComboBox is Deprecated.
		cmbxDoorType.addItemListener( this );
 
   	return cmbxDoorType;
   }
 
	public void itemStateChanged( ItemEvent e )
   {
   	if ( e.getStateChange() == ItemEvent.SELECTED )
   	{
			if ( boxDisplays[ cmbxDoorType.getSelectedIndex() ].equals( 0 ) )
			{
				setBoxDisplays( createDoubleDoorDisplay, 0 );
				createDoubleDoorDisplay.setVisible( true );
			}
 
			else if ( boxDisplays[ cmbxDoorType.getSelectedIndex() ].equals( 1 ) )
			{
				setBoxDisplays( createSingleDoorOptions, 1 );
				createSingleDoorOptions.setVisible( true );
			}
 
			else if ( boxDisplays[ cmbxDoorType.getSelectedIndex() ].equals( 2 ) )
			{
				setBoxDisplays( createDoubleDoorOptions, 2 );
				createDoubleDoorOptions.setVisible( true );
			}
 
   	}
   }
}