I swear I'm not a spelling nazi, but since the context seems to be
teaching a person who's not a native English speaker appropriate
terms, I feel like I should clarify that the term is "overriding,"
with two Rs.

And a question: in Java, we have interfaces that are implemented.
This is also called inheritance, right?

For clearing up - I am not using inheritance, I'm rather using composition.

I'll give an example...Classes(Parameter, Generator) are used as a
components of an Applet (those classes are aggregated in the applet
class). This classes depends somehow from each other, this dependance is
implemented in the methods of this classes.

So, the Generator component is repainted when its method change1 or
change2  is called, and this method is called by, other method (handleLR
or handleUD respectively)which are called when an event of scrollBar
status chenge happens.

[code]
//Parameter class prepares the panel for managing of some parameters by
changing the scrollBar's values
public class Parameter extends JPanel implements AdjustmentListener{

public JScrollBar scrbF;
public JScrollBar scrbA ;
public JTextField wartF ;
public JTextField wartA ;
Appl board1; //Appl is the class in which the object of Parameter class
would be aggregated

public Parameter(int a,int b,int c,int d,int e,int f,int g,int h,Appl
mainBoard) {
     scrbF = new JScrollBar(JScrollBar.HORIZONTAL, a, b, c, d);
     scrbA = new JScrollBar(JScrollBar.HORIZONTAL, e, f, g, h);

     wartF = new JTextField ();
     wartA = new JTextField ();

   board1=mainBoard;  //refference to the class in which the object of
Parameter class is aggregated

   Dimension size=new Dimension(400,80);
   setPreferredSize(size);

   GridLayout gridbg = new GridLayout(2,3);

   setLayout(gridbg);

   JLabel label1 = new JLabel("left-right:", JLabel.LEFT);
   add(label1);
   
   wartF.setEditable(false);
   wartF.setText(""+scrbF.getValue());
   add(wartF);
   
  scrbF.addAdjustmentListener(this);
  add(scrbF);

   JLabel label2 = new JLabel("up-down:", JLabel.LEFT);
   add(label2);
 
    wartA.setEditable(false);
    wartA.setText(""+scrbA.getValue());
    add(wartA);
   
    scrbA.addAdjustmentListener(this);
    add(scrbA);

    setBorder(BorderFactory.createTitledBorder("GO"));            
   }
   
   public void adjustmentValueChanged(AdjustmentEvent e) {
           Object source = e.getSource();
           if (source == scrbF) {
               int value;

               value=scrbF.getValue();
               wartF.setText(""+value);
               board1.handleLR(this); //usage of the method of Appl
class,   'this' reffers to Parameter object which would produce an event
           }
           if (source == scrbA){
               int value;

               value=scrbA.getValue();
               wartA.setText(""+value);
               board1.handleUD(this); ////usage of the method of Appl
class
           }
       }
}

///////////////////////////////////////////////

//class draws something
public class Generator extends JPanel{

   int fnx, fny, fnx1, fny1;

   public Generator() {

       fnx=10;
       fny=10;
       fnx1=30;
       fny1=30;

       Dimension size=new Dimension(400,300);
       setPreferredSize(size);

       repaint();
   }

   public void paintComponent(Graphics g) {

           super.paintComponent(g);
           Graphics2D g2D = (Graphics2D) g;
           g2D.setColor(Color.black);
           g2D.setBackground(Color.lightGray);
           g2D.drawLine((fnx1) , (fny1) , (fnx) , (fny) );
           fnx1=fnx;
           fny1=fny;
           }
    //following methods changes the parameters of drawLine()method
          public void change1(int a) {
             fnx=a*10;
             repaint();
            }
         public void change2(int a) {
             fny=a*10;
             repaint();
         }
}
///////////////////////////////////////////

//this class is an applet and agregates Parameter and Generator classes
and invoke some of their methods to make some changes.

public class Appl extends JApplet {

   JPanel contentPane;
   JPanel chartField;
   Parameter manager;
   Generator chartGenerator;

   public void init() {
       contentPane=new JPanel();
       contentPane.setLayout(new BoxLayout(contentPane,
BoxLayout.Y_AXIS));
     
//contentPane.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));

       manager= new Parameter(2,0,0,6,6,0,6,10,this);

       chartField=new JPanel();
       chartGenerator=new Generator();
       chartField.setLayout(new BorderLayout());
       chartField.setBorder(BorderFactory.createTitledBorder("Chart"));
       chartField.add(chartGenerator, BorderLayout.CENTER);
       
       contentPane.add(manager);
       contentPane.add(chartField);
       
       setContentPane(contentPane);
   }
   public void handleLR(Parameter x){
          int value;

          value=manager.scrbF.getValue();
          chartGenerator.change1(value);
   }
      public void handleUD (Parameter x){
          int value;

          value=manager.scrbA.getValue();
          chartGenerator.change2(value);
      }
}

[/code]

My program consist on this general design I've shown above.
Why it doesn't work as an applet? The following message is displayed by
the browser:Applet notinited,  but in JBuilder applet viewer it works very
well. And what you'll say? Any ideas?

For clearing up - I am not using inheritance, I'm rather using composition.

I'll give an example...Classes(Parameter, Generator) are used as a
components of an Applet (those classes are aggregated in the applet
class). This classes depends somehow from each other, this dependance is
implemented in the methods of this classes.

So, the Generator component is repainted when its method change1 or
change2  is called, and this method is called by, other method (handleLR
or handleUD respectively)which are called when an event of scrollBar
status chenge happens.

[code]
//Parameter class prepares the panel for managing of some parameters by
changing the scrollBar's values
public class Parameter extends JPanel implements AdjustmentListener{

public JScrollBar scrbF;
public JScrollBar scrbA ;
public JTextField wartF ;
public JTextField wartA ;
Appl board1; //Appl is the class in which the object of Parameter class
would be aggregated

public Parameter(int a,int b,int c,int d,int e,int f,int g,int h,Appl
mainBoard) {
     scrbF = new JScrollBar(JScrollBar.HORIZONTAL, a, b, c, d);
     scrbA = new JScrollBar(JScrollBar.HORIZONTAL, e, f, g, h);

     wartF = new JTextField ();
     wartA = new JTextField ();

   board1=mainBoard;  //refference to the class in which the object of
Parameter class is aggregated

   Dimension size=new Dimension(400,80);
   setPreferredSize(size);

   GridLayout gridbg = new GridLayout(2,3);

   setLayout(gridbg);

   JLabel label1 = new JLabel("left-right:", JLabel.LEFT);
   add(label1);
   
   wartF.setEditable(false);
   wartF.setText(""+scrbF.getValue());
   add(wartF);
   
  scrbF.addAdjustmentListener(this);
  add(scrbF);

   JLabel label2 = new JLabel("up-down:", JLabel.LEFT);
   add(label2);
 
    wartA.setEditable(false);
    wartA.setText(""+scrbA.getValue());
    add(wartA);
   
    scrbA.addAdjustmentListener(this);
    add(scrbA);

    setBorder(BorderFactory.createTitledBorder("GO"));            
   }
   
   public void adjustmentValueChanged(AdjustmentEvent e) {
           Object source = e.getSource();
           if (source == scrbF) {
               int value;

               value=scrbF.getValue();
               wartF.setText(""+value);
               board1.handleLR(this); //usage of the method of Appl
class,   'this' reffers to Parameter object which would produce an event
           }
           if (source == scrbA){
               int value;

               value=scrbA.getValue();
               wartA.setText(""+value);
               board1.handleUD(this); ////usage of the method of Appl
class
           }
       }
}

///////////////////////////////////////////////

//class draws something
public class Generator extends JPanel{

   int fnx, fny, fnx1, fny1;

   public Generator() {

       fnx=10;
       fny=10;
       fnx1=30;
       fny1=30;

       Dimension size=new Dimension(400,300);
       setPreferredSize(size);

       repaint();
   }

   public void paintComponent(Graphics g) {

           super.paintComponent(g);
           Graphics2D g2D = (Graphics2D) g;
           g2D.setColor(Color.black);
           g2D.setBackground(Color.lightGray);
           g2D.drawLine((fnx1) , (fny1) , (fnx) , (fny) );
           fnx1=fnx;
           fny1=fny;
           }
    //following methods changes the parameters of drawLine()method
          public void change1(int a) {
             fnx=a*10;
             repaint();
            }
         public void change2(int a) {
             fny=a*10;
             repaint();
         }
}
///////////////////////////////////////////

//this class is an applet and agregates Parameter and Generator classes
and invoke some of their methods to make some changes.

public class Appl extends JApplet {

   JPanel contentPane;
   JPanel chartField;
   Parameter manager;
   Generator chartGenerator;

   public void init() {
       contentPane=new JPanel();
       contentPane.setLayout(new BoxLayout(contentPane,
BoxLayout.Y_AXIS));
     
//contentPane.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));

       manager= new Parameter(2,0,0,6,6,0,6,10,this);

       chartField=new JPanel();
       chartGenerator=new Generator();
       chartField.setLayout(new BorderLayout());
       chartField.setBorder(BorderFactory.createTitledBorder("Chart"));
       chartField.add(chartGenerator, BorderLayout.CENTER);
       
       contentPane.add(manager);
       contentPane.add(chartField);
       
       setContentPane(contentPane);
   }
   public void handleLR(Parameter x){
          int value;

          value=manager.scrbF.getValue();
          chartGenerator.change1(value);
   }
      public void handleUD (Parameter x){
          int value;

          value=manager.scrbA.getValue();
          chartGenerator.change2(value);
      }
}

[/code]

My program consist on this general design I've shown above.
Why it doesn't work as an applet? The following message is displayed by
the browser:Applet notinited,  but in JBuilder applet viewer it works very
well. And what you'll say? Any ideas?