Newbie Question Regarding Layouts

  public void paintComponent(Graphics g)
      {
         super.paintComponent (g);
         
         X=-500; 																	  //X=-500 is Xmin
      	      
         g.setColor (Color.white);                                  //sets color of graphs background
         g.fillRect (0,55,size,size);                               //draws the graph area background
			
         g.setColor (Color.black);                                  //sets color of axis
         g.drawLine (size/2,55,size/2,size+55);                     //draws vertical axis
         g.drawLine (0,((size+50)/2)+100,size,((size+50)/2)+100);   //draws horizontal axis
                					
         while (X<500)                                               //X=500 is Xmax
         {
             	             
            Y = A*Math.pow(X,3) + B*Math.pow(X,2) + C*X + D;         //AX^3 + BX^2 + CX + D
            
				g.setColor (Color.red);                                  //sets color of the graph
            int Y2 = (int)Y;
            int X2 = (int)X;                                         //X and Y must be integers to fit in drawline command.
				
            X=X+0.01;                                                //
            //System.out.println (X2+" , "+Y2);                      //may be used to optionally dysplay values for X and Y
            
            g.drawLine ((Y2+(size/2)),(X2+((size+50)/2)+100),(Y2+(size/2)),X2+((size+50)/2)+100); 
                                                                     //draws the graph
          }
      }
       
       private class PlotterAdapter implements ActionListener
      {
          public void actionPerformed (ActionEvent event)
         {
            String text1 = input1.getText();                         //gets a string from user
            String text2 = input2.getText();                         //
            String text3 = input3.getText();                         //
            String text4 = input4.getText();                         //gets a string from user
				
            A = Double.parseDouble (text1);                          //converts string to Double
        		B = Double.parseDouble (text2);                          //
            C = Double.parseDouble (text3);                          //
            D = Double.parseDouble (text4);                          //converts string to Double
				
				repaint();                                               //redraws the graph when button is pressed
         }
      }