problem with drawline using arrow key

[shazlin]

well, it works fine when i go up and down but when i using left or right arrow key. the all line shift to left or right. can anyone could help me with this?


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

public class KeyEvents extends JPanel implements MouseMotionListener {
Point p;
int y=100, x=100;
int a = x, b = y;
Graphics g;
public KeyEvents () {
addKeyListener(new KeyAdapter() {
public void keyPressed(KeyEvent e) {
switch (e.getKeyCode()) {
case KeyEvent.VK_UP: b-=10;
break;
case KeyEvent.VK_DOWN: b+=10;
break;
case KeyEvent.VK_LEFT: a-=10;

break;
case KeyEvent.VK_RIGHT: a+=10;
}
repaint();
}
});
this.addMouseMotionListener(this);

}
public void mouseMoved(MouseEvent e) {
}
public void mouseDragged(MouseEvent e){

}
public void paintComponent(Graphics g) {
super.paintComponent(g);

g.drawLine(x, y, a, b);
}
}

Thank You

[shazlin]

i cant draw a square with my code