Java - Conectar un jframe con otro

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {

   Jframe2 oforma = new Jframe2();

   oforma.setVisible(true);

}

package trivia;

import java.awt.EventQueue;

import java.awt.Font;

import javax.swing.GroupLayout;

import javax.swing.GroupLayout.Alignment;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JPanel;

import javax.swing.border.EmptyBorder;

@SuppressWarnings("serial")

public class lobby extends JFrame {

	private JPanel contentPane;

	/**

	 * Launch the application.

	 */

	public static void main(String[] args) {

		EventQueue.invokeLater(new Runnable() {

			public void run() {

				try {

					lobby frame = new lobby();

					frame.setVisible(true);

				} catch (Exception e) {

					e.printStackTrace();

				}

			}

		});

	}

	/**

	 * Create the frame.

	 * @return

	 */

	public lobby() {

		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

		setBounds(100, 100, 450, 300);

		contentPane = new JPanel();

		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));

		setContentPane(contentPane);

		JButton Inicio = new JButton("Inicio");

		Inicio.setFont(new Font("Arial Narrow", Font.BOLD, 15));

		JLabel banner = new JLabel("Trivia");

		banner.setFont(new Font("Arial", Font.BOLD, 29));

		JLabel mensaje = new JLabel("Cuantas preguntas puedes hacer en 90 minutos");

		mensaje.setFont(new Font("Arial Narrow", Font.BOLD, 12));

		GroupLayout gl_contentPane = new GroupLayout(contentPane);

		gl_contentPane.setHorizontalGroup(

			gl_contentPane.createParallelGroup(Alignment.LEADING)

				.addGroup(gl_contentPane.createSequentialGroup()

					.addGroup(gl_contentPane.createParallelGroup(Alignment.LEADING)

						.addGroup(gl_contentPane.createSequentialGroup()

							.addGap(39)

							.addComponent(banner))

						.addGroup(gl_contentPane.createSequentialGroup()

							.addGap(164)

							.addComponent(Inicio)))

					.addContainerGap(120, Short.MAX_VALUE))

				.addGroup(Alignment.TRAILING, gl_contentPane.createSequentialGroup()

					.addContainerGap(108, Short.MAX_VALUE)

					.addComponent(mensaje)

					.addGap(98))

		);

		gl_contentPane.setVerticalGroup(

			gl_contentPane.createParallelGroup(Alignment.LEADING)

				.addGroup(gl_contentPane.createSequentialGroup()

					.addGap(29)

					.addComponent(banner)

					.addGap(57)

					.addComponent(Inicio)

					.addGap(40)

					.addComponent(mensaje)

					.addContainerGap(48, Short.MAX_VALUE))

		);

		contentPane.setLayout(gl_contentPane);

	}

}