Questo è il codice completo..

codice:
import javax.swing.JApplet;import javax.swing.JPanel;
import javax.swing.JLabel;
import javax.swing.JRadioButton;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;




publicclasskmkextends JApplet{


/**
	 * Create the applet.
	 */
	public kmk() {
		getContentPane().setLayout(null);

		final JPanel panel = new JPanel();
		panel.setBounds(0, 0, 450, 300);
		getContentPane().add(panel);
		panel.setLayout(null);

		JRadioButton rdbtnNewRadioButton = new JRadioButton("Option A");
		rdbtnNewRadioButton.setBounds(20, 49, 141, 23);
		panel.add(rdbtnNewRadioButton);

		JLabel lblDomanda = new JLabel("1 domanda");
		lblDomanda.setBounds(174, 6, 70, 16);
		panel.add(lblDomanda);

		JRadioButton rdbtnNewRadioButton_1 = new JRadioButton("Option B");
		rdbtnNewRadioButton_1.setBounds(20, 96, 141, 23);
		panel.add(rdbtnNewRadioButton_1);

		JRadioButton rdbtnNewRadioButton_2 = new JRadioButton("Option C");
		rdbtnNewRadioButton_2.setBounds(20, 157, 141, 23);
		panel.add(rdbtnNewRadioButton_2);



		final JPanel panel_1 = new JPanel();
		panel_1.setBounds(-1240, -800, 450, 300);
		getContentPane().add(panel_1);
		getContentPane().setVisible(true);
		panel_1.setLayout(null);


		JRadioButton rdbtnNewRadioButton_11 = new JRadioButton("Option A");
		rdbtnNewRadioButton_11.setBounds(20, 49, 141, 23);
		panel_1.add(rdbtnNewRadioButton_11);

		JLabel lblDomanda_11 = new JLabel("2 domanda");
		lblDomanda_11.setBounds(174, 6, 70, 16);
		panel_1.add(lblDomanda_11);

		JRadioButton rdbtnNewRadioButton_111 = new JRadioButton("Option B");
		rdbtnNewRadioButton_111.setBounds(20, 96, 141, 23);
		panel_1.add(rdbtnNewRadioButton_111);

		JRadioButton rdbtnNewRadioButton_22 = new JRadioButton("Option C");
		rdbtnNewRadioButton_22.setBounds(20, 157, 141, 23);
		panel_1.add(rdbtnNewRadioButton_22);

		final JPanel panel_2 = new JPanel();
		panel_2.setBounds(-1240, -800, 450, 300);
		getContentPane().add(panel_2);
		panel_2.setLayout(null);

		JButton btnNewButton = new JButton("Next");
		btnNewButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				getContentPane().remove(panel);
				getContentPane().add(panel_1);
				validate();


			}
		});
		btnNewButton.setBounds(327, 265, 117, 29);
		panel.add(btnNewButton);


	}



}