import javax.swing.*;

import java.awt.event.ActionListener;

import java.awt.event.ActionEvent;

public class popupWindows{

    JFrame mainWindow;

    public popupWindows(){

        mainWindow = new JFrame("pop up window");

        //mainWindow.setBounds(10,10,10,10);

        JButton JB = new JButton("PopUp");

        JB.addActionListener(new creatNewWindow());

        mainWindow.setVisible(true);

        mainWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        mainWindow.add(JB);

        mainWindow.pack();

    }

    class creatNewWindow implements ActionListener{

        public void actionPerformed(ActionEvent e){

            new popupWindows().mainWindow.setBounds(100,100,100,100);

        }

    }

    public static void main(String[] args){

        new popupWindows();

    }

}