Hi folks,
I have a small problem.
1) The initial oval, from paintComponent, isn't draw
2) If the applet window looses focus, even the rectangle disappears.
I suppose it's a problem of instance. But I can't see what's
wrong.
Can anybody tell me why, please?
Thanks in advance.
-steeve.

Here is my code:

////////////////////// begin cut ////////////////////////
import java.awt.BorderLayout;
import java.awt.Graphics;

import javax.swing.JComponent;
import javax.swing.JPanel;
import javax.swing.JApplet;
import javax.swing.JButton;

public class binom_swing extends JApplet {

    private JPanel jContentPane = null;
    private JPanel jPaneltop = null;
    private JPanel jPanelbottom = null;
    public Graphics g;

    private JButton jButton1 = null;

    public binom_swing() {
        super();
    }

    public void init() {
        setSize(800,700);
        setContentPane(getJContentPane());
    }

    private JPanel getJContentPane() {
        if(jContentPane == null) {
            jContentPane = new JPanel();
            jContentPane.setLayout(new BorderLayout());
            jContentPane.setPreferredSize(new java.awt.Dimension(800,700));
            jContentPane.add(getJPaneltop(), java.awt.BorderLayout.NORTH);
            jContentPane.add(getJPanelbottom(), java.awt.BorderLayout.SOUTH);
        }
        return jContentPane;
    }

    private JPanel getJPaneltop() {
        if (jPaneltop == null) {
            jPaneltop = new JPanel();
            jPaneltop.setPreferredSize(new java.awt.Dimension(800,700));
            jPaneltop.add(getJButton1(), null);
        }
        return jPaneltop;
    }

    private JPanel getJPanelbottom() {
        if (jPanelbottom == null) {
            jPanelbottom = new JPanel();
            jPanelbottom.setPreferredSize(new java.awt.Dimension(800,650));
        }
        return jPanelbottom;
    }

    private JButton getJButton1() {
        if (jButton1 == null) {
            jButton1 = new JButton();
            jButton1.setText("rect");
            jButton1.addActionListener(new java.awt.event.ActionListener() {
                public void actionPerformed(java.awt.event.ActionEvent e) {
                    g = jPanelbottom.getGraphics();
                   DrawOnJComponent canvas = new     DrawOnJComponent (g);
                   canvas.Rectangle();
                }
            });
        }
        return jButton1;
    }

}

class DrawOnJComponent extends JComponent {

          private Graphics g;

          DrawOnJComponent(Graphics g){
          this.g=g;
      }

      public void paintComponent(Graphics g){
          g.drawOval(50,50,250,300);  // draw initial OVAL
      }

      public void Rectangle() {
          g.drawRect (50,50,250,300);  // draw RECTANGLE
      }
   
}
////////////////////// end cut ////////////////////////