Confuced when import packages...

Code :

---

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class MyFrame extends JFrame{
	JButton btYes;
	JButton btNo;
	JButton btCancel;
 
	MyFrame(){
		setLayout(new FlowLayout());
 
		btYes=new JButton("Yes");
		btYes.addActionListener(new MyAction());
		btNo =new JButton("No");
		btCancel=new JButton("Cancel");
 
		add(btCancel);
		add(btNo);
		add(btYes);
		pack();
	}
	public static void main(String args[]){
	new MyFrame().setVisible(true);
	}
}
class MyAction implements ActionListener{
	public void actionPerformed(ActionEvent evt){
		JOptionPane.showMessageDialog(null,"You pressed Yes Button");
	}
}

---

:confused:
Dear java friends; I'm confused when import package using * .
When we import awt package by import java.awt.*; as I know it imports all the classes in awt package. If so why we have to call import java.awt.event.*; in this program. Please be kind to help me to solve this problem.

What problem?

db

More here (link below)
Packages

db