import javax.swing.JPanel;
import javax.swing.JFrame;
import java.awt.event.MouseListener;
import java.awt.event.MouseEvent;
import java.awt.Dimension;
import java.awt.Color;
import java.awt.Container;
import javax.swing.JApplet;

class EcouteCouleur implements MouseListener {
    Container panneau;
    EcouteCouleur(Container panneau) {
	this.panneau = panneau;
    }
    
    public void mouseEntered(MouseEvent e) {
	panneau.setBackground(Color.GREEN);
    }
    
    public void mouseExited(MouseEvent e)  {
	panneau.setBackground(Color.RED);
    }
    
    public void mousePressed(MouseEvent e)  {}
    
    public void mouseReleased(MouseEvent e) {}
    
    public void mouseClicked(MouseEvent e) {}
}

class PanneauCouleur extends JPanel { 
    PanneauCouleur() {
	setPreferredSize(new Dimension(200, 200));
	addMouseListener(new EcouteCouleur(this));
	setBackground(Color.RED);
    }
}    

public class EntenduA extends JApplet {
  public void init()
    { 
	setContentPane(new PanneauCouleur());
    }
}