dispose method

[jumpman8947]

I created a program where when I click a button another screen shows up but the only problem I'm having is the first screen isn't going away. I tried to use the dispose method but I come up with an error don't know why though.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class MainScreen extends JFrame
{
	private  JTextField field1;
	private JLabel label1;
	private JLabel label2;
	private JButton button1;
	private JButton button2;
	private JComboBox box1;
	private JLabel imageIcon;


	public MainScreen()
	{
		field1 = new JTextField("Welcome");
		setLayout(null);

		Dimension size1 = field1.getPreferredSize();
		//Dimension size2 = label1.getPreferredSize();

		//Build field1
		field1.setBounds(400, 15, 220, 75);
		field1.setBackground(new Color(0, 102, 102));
		field1.setFont(new Font("Times New Roman", 1, 24));
		field1.setEditable(false);
		add(field1);

		//Build button1
		button1 = new JButton("EXIT");
		button1.setBounds(400, 620, 220, 75);
		button1.setBackground(new Color(0, 0, 0));
		button1.setForeground(new Color(255, 0, 0));
		button1.addActionListener(new button1Listener());
		add(button1);

		//Build button2
		button2 = new JButton("Click To Enter");
		button2.setBounds(350, 300, 220, 75);
		button2.addActionListener(new button2Listener());
		add(button2);

		//Build label1
		label1 = new JLabel();
		label1.setIcon(new ImageIcon ("bible3.gif"));
		label1.setBounds(0, 15, 600, 600);
		add(label1);

		//Build label2
		label2 = new JLabel();
		label2.setIcon(new ImageIcon ("seed.jpg"));
		label2.setBounds(707, 100, 400, 400);
		add(label2);

		//Build ComboBox
		box1 = new JComboBox();
		box1.setModel(new DefaultComboBoxModel(new String[]
		{
			"Gospel", "Raeggae", "Hip-Hop"
		}));
		box1.setBounds(700, 0, 89, 50);
		add(box1);

		setSize(1100, 770);
		setTitle("Main Screen");
		setBackground(new Color(204, 102, 0));
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		getContentPane().setBackground(new Color(204, 102, 0));





		setVisible(true);



	}

	private class button1Listener implements ActionListener
				{
					public void actionPerformed(ActionEvent e)
					{
						System.exit(0);
					}

				}
	private class button2Listener implements ActionListener
				{
					public void actionPerformed(ActionEvent e)
					{
						MiddleScreen midScr = new MiddleScreen();
						midScr.setVisible(true);
						MainScreen.dispose();

					}

				}








	public static void main(String[] args)
	{
		new MainScreen();
	}



}

The error I'm getting is "non-static method dispose() can't be referenced from a static context MainScreen.dispose();"