swing - Java JFRAME button then new gui

So, I try to make a Java Program, that when you run it, the first screen will be welcome, under it button "login", under it "register". And now I need to figure how if I press one of these buttons, how can I call new GUI, which I will define somewhere. (e.g) i call register button and it calls new gui where is normal things that asks you when you register(login,email,pass,date of birth)

EDIT: problem solved, but there is a one more thing. How can I close the first window?

This is my code so far:

import javax.swing.*;
import java.awt.*;
import java.awt.GridLayout;
import java.awt.BorderLayout;

import javax.swing.BorderFactory;
import java.awt.event.*;
import java.util.*;
import java.io.*;
import java.util.*;
import javax.swing.JFrame;
import java.awt.Dimension;
public class Gui extends JFrame
{
    private JLabel lab1,lab2;

    private JButton butt1,butt2;
    private JPanel p1,p2;
    public static void main(String[] args)
    {
        Gui okno = new Gui();
        //vytáhne z defaultního monitoru width a height
        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
        int width = (int) screenSize.getWidth();
        int height = (int) screenSize.getHeight();
        //velikost okna

        Dimension appSize = new Dimension(210,250);
        okno.setPreferredSize(appSize);
        //nastavení na stred
        okno.setLocation((width/2)-105,(height/2)-125);
        okno.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        okno.setVisible(true);
        //okno.setLocationRelativeTo(null); todle dá do středu obrazovky jen první body x a y od kterejch se to odvíjí
        okno.setResizable(false);
        okno.pack();


    }

    public Gui(){
       super("Jméno hry vole");       
       setLayout(new BorderLayout(20,20));
       /////////////////////////////////////////////////////////////////
       // p1
       p1 = new JPanel();
       add(p1,BorderLayout.NORTH);
       lab1 = new JLabel("Welcome",SwingConstants.CENTER); //centr labelu

       lab2 = new JLabel("Created by DECHKR",SwingConstants.CENTER); //centr labelu
       lab1.setFont(new Font("Serif", Font.PLAIN, 36)); //velikost fontu
       p1.add(lab1);
       //p2
       p2 = new JPanel(new GridLayout(2,1,0,5));
       add(p2,BorderLayout.SOUTH);

       Dimension d = new Dimension(210,75);
       butt1 = new JButton("Login");
       butt1.setPreferredSize(d);

       butt2 = new JButton("Register");
       butt2.setPreferredSize(d);
       p2.add(butt1);
       p2.add(butt2);


          butt1.addActionListener(new ActionListener(){
             public void actionPerformed(ActionEvent evt){
                //Gui okno = new Gui();
                //System.exit(0);  endne celej jvm proces




             }

         });

         butt2.addActionListener(new ActionListener(){
             public void actionPerformed(ActionEvent evt){



             }

         });
}

Answer

I am still learning, but want to try and help.I would try making a new JFrame in the actionPerformed method of the listener. I also would probably make separate classes for your button action listeners otherwise you won't be able to perform separate task. I.E.

 class button1Listener implements ActionListener {

    public void actionPerformed(ActionEvent ev){
         JFrame frame = new JFrame();
          (ETC CODE...)
   }
}