boolean resizable = true;
    boolean closeable = true;
    boolean maximizable  = true;
    boolean iconifiable = true;
    int width = 200;
    int height = 50;
    JInternalFrame iframe = new JInternalFrame("",
	 resizable, closeable, maximizable, iconifiable);
    iframe.setSize(width, height);
    
    // Add component to internal frame.
    
    // Add internal frame to desktop.
    JDesktopPane desktop = new JDesktopPane();
    desktop.add(iframe);


 // eigen voorbeeld =>

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

class ExampleInternalFrames extends JFrame{

	ExampleInternalFrames( ){
	// call super JFrame instance
		super("Voorbeeld internal frames");
	// get frame container
		Container FRAMECONTAINER = getContentPane( );
	// create desktop
		JDesktopPane DESKTOPPANE = new JDesktopPane( );
	// add desktop to container
		FRAMECONTAINER.add(DESKTOPPANE );

	// create panel
		JPanel PANEL = new JPanel( );
	// create internal frame to place PANEL (via desktop)
		JInternalFrame INTERNALFRAME = new JInternalFrame("an internal frame",
								true,true, true, true); 
	// position and size internal frame
		INTERNALFRAME.setLocation(0,0);	
		INTERNALFRAME.setSize(200,100);	

	// add internal frame to desktoppane
		DESKTOPPANE.add( INTERNALFRAME );

		setSize(400, 300);
		setVisible(true );

	}// end of constructor

	public static void main(String args[]){	new ExampleInternalFrames( );}
}