import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;

class Spot {
    public int size;
    public int x, y;
    
    public Spot(int size) {
	this.size = size;
	this.x = -1;
	this.y = -1;
    }
} 

public class ClickMe extends Applet implements MouseListener {
    private Spot spot = null;
    private static final int RADIUS = 7;

    public void init() {
	addMouseListener(this);
    }

    public void paint(Graphics g) {
	// draw a black border and a white background
	g.setColor(Color.white);
	g.fillRect(0, 0, getSize().width - 1, getSize().height - 1);
	g.setColor(Color.black);
	g.drawRect(0, 0, getSize().width - 1, getSize().height - 1);

	// draw the spot
	g.setColor(Color.red);
	if (spot != null) {
	    g.fillOval(spot.x - RADIUS,
		       spot.y - RADIUS,
		       RADIUS * 2, RADIUS * 2);
	}
    }
    public void mousePressed(MouseEvent event) {
	if (spot == null) {
	    spot = new Spot(RADIUS);
	}
	spot.x = event.getX();
	spot.y = event.getY();
	repaint();
    }
    public void mouseClicked(MouseEvent event) {}
    public void mouseReleased(MouseEvent event) {}
    public void mouseEntered(MouseEvent event) {}
    public void mouseExited(MouseEvent event) {}
}