国际象棋棋盘的小问题

import java.awt.*;
import javax.swing.*;
public class Chessboard extends JApplet {
        int baseXPosition,baseYPosition;
        int currentXPosition,currentYPosition;
        public void init(){
         baseXPosition=40;
         baseYPosition=40;
         setBackground(Color.black);
        }
        public void paint(Graphics g){
         currentXPosition=baseXPosition;
         currentYPosition=baseYPosition;
         for(int row=0;row<8;row++){
         currentXPosition=baseXPosition+row*40;
         for(int column=0;column<8;column++){
         if((column+row)%2==0)
         g.setColor(Color.green);
         else
         g.setColor(Color.black);
         currentYPosition=baseXPosition+column*40;
         g.fillRect(currentXPosition,currentYPosition,currentXPosition+40,currentYPosition+40);
         }
         }
        }
}
  这是.java源程序<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>
<head>
</head>
<body bgcolor="000000">
<center>
<applet
code = "Chessboard.class"
width = "400"
height = "400"
>
</applet>
</center>
</body>
</html>
这是.html源程序 怎么运行后的图形右边和下边多了这么多??高手们帮帮忙哈.