Ok thats right. I initialize the DrawingPanel in the
MainEngineeringToolFrame like:

private DrawingPanel mDrawingPnl = new DrawingPanel();

other operations for mDrawingPnl in the MainEngineeringToolFrame class
are like below:

public void initComponents()  //called in constructor
{
 // some code.
 mDrawingPnl.setBounds(50,50,200,400);
 mDrawingPnl.setVisible(true); // I dont know =]
}

public Component buildPanel()  //function is for adding components to
the defined layout with coordinates.
//I ve used JGoodies forms for layout manage. dont need to focus on
that
{
 //some code
 PanelBuilder panel = new PanelBuilder(layout);
 //a lot of builder.add(....
 builder.add(mDrawingPnl, cc.xy(5,1));  //coordinates.

 return builder.getPanel();
}

main
{
 //some code
 frame.add(frame.buildPanel());
 frame.setVisible(true);
}

And I replaced the DrawingPanel class like this

public class DrawingPanel extends JPanel implements MouseListener,
MouseMotionListener
{
  public MainEngineeringToolFrame obj = new
MainEngineeringToolFrame();

but now I m getting a lot of nullPointer exceptions refering to the
variables derived from obj.
Such as in paint function

public void paint(Graphics g)
{
 super.paint(g);
 g.setColor(obj.getMCurrentColor()); //used the getter method of Color
currentColor variable
}

4 exceptions occured in this line
g.setColor(obj.getMCurrentColor());

saying:
Exception in thread "AWT-EventQueue-0' java.lang.NullPointerException

4 exceptions occured right after each other in one time.

Your helps are appriciated. Thanx again.
and help again pls :)

best regards
metan

well the problem is because of the  MainEngineeringToolFrame obj = new
MainEngineeringToolFrame(); object after debugging. but i am still not
able to understand why..

well in this decleration it is expected that a null pointer exception
will occur

public  MainEngineeringToolFrame obj;

but the program window is visible and by buttons and stuff are
available. However any action is taken it is giving a null pointer
exception to the

obj.something

declerations. Ok I understand that. It is normal
but when i initialize the object with its constructor like

public  MainEngineeringToolFrame obj = new MainEngineeringToolFrame();

it is giving the

Exception In thread "SyntheticImageGenerator"
java.lang.OutOfMemoryError: Java heap space

error and terminates the program without initialization. What would i
have to do?

In addition I think the declarations and initializations of
DrawingPanel object in the MainEngineeringToolFrame is correct.. if not
may be the problem can be solved there..

necessary code is below:

public class MainEngineeringToolFrame extends JFrame implements
ActionListener.
{
  //Some Code...
  private DrawingPanel mDrawingPnl = new DrawingPanel();

  public MainEngineeringToolFrame()
  {
     super("HELP PLS");
     setBounds(120,300,1024,428);
     setResizable(false);
     initComponents();
     setVisible(true);

  }
 public void initComponents()  //called in constructor
{
 // some code.
 mDrawingPnl.setBounds(50,50,200,400);
 mDrawingPnl.setVisible(true); // I dont know =]

}

//function is for adding components to the defined layout with
coordinates.
//I ve used JGoodies forms for layout manage. dont need to focus on
public Component buildPanel()
{
 //some code
 PanelBuilder panel = new PanelBuilder(layout);
 //a lot of builder.add(....
 builder.add(mDrawingPnl, cc.xy(5,1));  //coordinates.

 return builder.getPanel();

}
  //Some Code...

  public static void main(String[] args)
  {
     System.out.println("***Main function loaded.");
     MainEngineeringToolFrame frame = new MainEngineeringToolFrame();
     System.out.println("***Object created.");
//      frame.setTitle
//      frame.setResizable
//      getContentPane
//      add(....
     frame.add(frame.buildPanel());
     setVisible(true);
  }

}

Second class

public class DrawingPanel extends JPanel implements MouseListener,
MouseMotionListener
{
  MainEngineeringToolFrame obj = new MainEngineeringToolFrame();

  public DrawingPanel()
  {
     super();
     addMouseListener(this);
     addMouseMotionListener(this);
     setLayout(null);
  }

  public void paint(Graphics g)
  {
     super.paint(g);
     g.setColor(obj.getMCurrentColor()); //used the getter method of
Color currentColor variable
     //Exception will occur.

  }
   //implemented methods.

}

Any suggestions are very appriciated.
Thanx
regards.