import javax.swing.JFrame;
import javax.swing.JButton;
import java.awt.Graphics;
import java.awt.Color;
import java.awt.event.MouseListener;
import java.awt.event.MouseEvent;

class Program01 extends JFrame {
	final static long serialVersionUID = 1;
	JButton button = new JButton("Kattints");
	Program01() {
		button.setLocation(25, 30);
		button.setSize(100, 30);
		button.addMouseListener(new MouseListener(){
			public void mouseExited(MouseEvent evt) { }
			public void mouseEntered(MouseEvent evt) { }
			public void mouseReleased(MouseEvent evt) { }
			public void mousePressed(MouseEvent evt) { }
			public void mouseClicked(MouseEvent evt) {
				buttonMouseClick(evt);
			}			
		});
		
		setLayout(null);
		add(button);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setSize(400, 300);
		setVisible(true);
	}
	public void buttonMouseClick(MouseEvent evt) {
		Graphics g = getGraphics();
		g.setColor(Color.BLUE);
		g.fillRect(150, 30, 100, 30);		
	}
	public static void main(String args[]) {
		new Program01();
	}
}