textfield error

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextfield;

public class testingg {

    public static void main(String[] args) {

        final JFrame frame = new JFrame();

    	JPanel panel = new JPanel();

	JTextfield nameField = new JTextField();

        JButton button1 = new JButton();

        final JLabel label = new JLabel("Hello text");

        label.setVisible(false);
        frame.add(panel);
        panel.add(button1);
        panel.add(label);
        frame.setSize(200,200);
        frame.setVisible(true);
        panel.add(nameField);

        button1.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent arg0) {

                label.setVisible(true);
            }
        });

    }

}