import java.awt.*;
import java.awt.event.*;

import javax.swing.*;
public class layout extends JFrame {
private JButton lb,cb,rb;
private FlowLayout lay;
private Container container;

public layout(){
	super("Layout");
	lay= new FlowLayout();
	container= getContentPane();
	setLayout(lay);
	
	lb= new JButton("left");
	add(lb);
	lb.addActionListener(new ActionListener(){
		public void actionPerformed(ActionEvent event) {
			lay.setAlignment(FlowLayout.LEFT);
			lay.layoutContainer(container);
		}
	});
	
	cb= new JButton("center");
	add(cb);
	cb.addActionListener(new ActionListener(){
		public void actionPerformed(ActionEvent event) {
			lay.setAlignment(FlowLayout.CENTER);
			lay.layoutContainer(container);
		}
	});
	
	rb= new JButton("right");
	add(rb);
	rb.addActionListener(new ActionListener(){
		public void actionPerformed(ActionEvent event) {
			lay.setAlignment(FlowLayout.RIGHT);
			lay.layoutContainer(container);
		}
	});
}
	
public static void main(String args[]){
	layout ob=new layout();
	ob.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	ob.setSize(300,100);
	ob.setVisible(true);
}
	
	
}