Problem with actionperformed callback

I tried to create function, what shows textdialog, when client press the buton, but the problem is that i have defined frame under public static void main and in ActionPerformed callback first parameter "frame" is undefined. How could i fix this?

import java.awt.*;































































































































import java.awt.event.*;































































































































import java.applet.Applet;































































































































import javax.swing.*;

public class Vestlus extends Applet implements ActionListener {































































































































TextField tf = new TextField("");































































































































Button nupp = new Button(" Sisesta ");

public Vestlus()































































































































{































































































































add(tf);































































































































add(nupp);































































































































nupp.addActionListener(this);

}































































































































public void actionPerformed(ActionEvent e)































































































































{































































































































if(e.getSource() == nupp)































































































































{































































































































JOptionPane.showMessageDialog(frame,"Hoiatus","Vää rtused ei klapi!", JOptionPane.INFORMATION_MESSAGE);

}































































































































}































































































































public static void main(String args[])































































































































{

JFrame frame = new JFrame("Project LA");































































































































frame.add(new Vestlus());































































































































frame.setSize(300,200);































































































































frame.setVisible(true);































































































































frame.setDefaultCloseOperation(1);

}

}