Java Code

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

 public class DrawRectsLoop extends JApplet
 {
    int x=0;
    int y=0;
    int width=300;
    int height=200;
    int spacing = 20;

   public void paint ( Graphics g )
   {
      while( width > spacing && height > spacing )
      {
		 g.drawRect( x,y, width, height );
		 x = x + spacing;
		 y = y + spacing;
		 width = width - 2 * spacing;
		 height = height - 2 * spacing;
      }
   }
 }