This is the checkerboard, and here is the code ...


import java.awt.*;
import java.awt.event.*;

public class checkerboard extends java.applet.Applet{
	int row;
	int col;

	public void paint( Graphics g ){
		g.setColor(Color.black);
		g.fillRect(0,0,500,500);
		g.setColor(Color.red);
		
		for(row=0;row<=3;row++){
	 		for(col=0;col<=3;col++){
  				g.fillRect(col*100,row*100,50,50);
  				g.fillRect(col*100+50, row*100+50, 50,50);
 			}
		}
	}
}