import java.awt.*;
import java.applet.Applet;//tells the browser its an applet lol

public class Rectangles extends Applet
       {

public void paint(Graphics g) //you will always need Graphics g so the applet knows its a drawing
              {
              int left = 5;
              int top = 5;
              int width = (this.size().width) / 2 - 10; //the width of the rectangles
              int height = this.size().height - 10; //the height of the rectangles
              drawRects(g, left, top, width, height); //obvious what it does
              left = width + 15;
              drawFilledRects(g, left ,top, width, height); //filles the recangles
              }
       public void drawRects(Graphics g, int l, int t, int w, int h)
              {
              while (h > 0)
                    {
                    g.drawRect(l, t, w, h);
                    l += 10; //length
                    t += 10; //idk lol
                    w -= 20; //width
                    h -= 20; //height
                    }
              }
public void drawFilledRects(Graphics g, int l, int t, int w, int h)
       {
              g.setColor(Color.black); //the colour it sets - try green etc
              while (h > 0)
                    {
                    g.fillRect(l, t, w, h);
                    l += 10; //length
                    t += 10;
                    w -= 20; //width
                    h -= 20; //height
                    if (g.getColor() == Color.white) //the other colour etc
                       g.setColor(Color.black);
                    else
                       g.setColor(Color.white);
                    }
          }
}