Error when I push a button in an applet

Question

hi,
I created a class wich extends JApplet. I made several button objects and added actionlisteners to them. One button is supposed to create an object of the class Outcall. I wrote this Outcall class and put it into the directory.
Now when I make an object of this class in a console application (in the main method) there's no problem. But when I do it attached to a actionlistener i get an error in my appletviewer window but the program compiles fine.
can anyone help me
thanx,
olivier
here's my applet
import javax.telephony.*;
import javax.telephony.events.*;
import javax.telephony.media.*;
import javax.telephony.media.events.*;
import java.net.*;
import java.util.*;
import javax.sound.sampled.*;
import java.io.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Test extends JApplet implements ItemListener{
//klasse variabelen
JLabel tekiezennummer;
JTextField nummerinput;
JLabel statuslabel;
JTextField status;     
JPanel kaarten;
String input="";
final static String TELEFOONKIEZER = "TELEFOONKIEZER";
final static String ANTWOORDAPPARAAT = "ANTWOORDAPPARAAT";
//actionlisteners
class luister implements ActionListener{
     public void actionPerformed(ActionEvent e){
     input += ((JButton)e.getSource()).getText();
     nummerinput.setText(input);
class belluister implements ActionListener{
     public void actionPerformed(ActionEvent e){
          Outcall gesprek=new Outcall(input);
          gesprek.bellen();
class clearluister implements ActionListener{
     public void actionPerformed(ActionEvent e){
          input="";
          nummerinput.setText("");
luister luisteraar=new luister();
belluister belluisteraar=new belluister();
clearluister clearluisteraar=new clearluister();
//init
     public void init(){
     Container doos = getContentPane();
          String comboBoxItems[] = { TELEFOONKIEZER, ANTWOORDAPPARAAT };
          JPanel paneel = new JPanel();
          JComboBox keuze = new JComboBox(comboBoxItems);
          keuze.setEditable(false);
          keuze.addItemListener(this);
          paneel.add(keuze);
          doos.add(paneel, BorderLayout.NORTH);
          kaarten = new JPanel();
          kaarten.setLayout(new CardLayout());
          //alles wat met de telefoonkiezer te maken heeft
          JPanel p1 = new JPanel();
          JPanel paneel1=new JPanel();
          JPanel paneeltje1=new JPanel();
          paneeltje1.setLayout(new FlowLayout());
          tekiezennummer=new JLabel("Het te bellen nummer");
          paneeltje1.add(tekiezennummer);
          nummerinput=new JTextField();
          nummerinput.setColumns(20);
          paneeltje1.add(nummerinput);
          JButton clear=new JButton("Clear");
          clear.addActionListener(clearluisteraar);
          paneeltje1.add(clear);
          JPanel paneeltje2=new JPanel();
          paneeltje2.setLayout(new FlowLayout());
          statuslabel=new JLabel("Status");          
          paneeltje2.add(statuslabel);
          status=new JTextField();
          status.setColumns(20);
          status.setEditable(false);
          paneeltje2.add(status);
          paneel1.add(paneeltje1,BorderLayout.NORTH);
          paneel1.add(paneeltje2,BorderLayout.CENTER);
          JPanel paneel2=new JPanel();
          paneel2.setLayout(new GridLayout(0,3));
                    for(int i=1;i<=3;i++){
                    Integer opdruk=new Integer(i);
                    String text=opdruk.toString();
                    JButton knop=new JButton(text);
                    knop.addActionListener(luisteraar);
                    paneel2.add(knop);
               for(int i=4;i<=6;i++){
                    Integer opdruk=new Integer(i);
                    String text=opdruk.toString();
                    JButton knop=new JButton(text);
                    knop.addActionListener(luisteraar);
                    paneel2.add(knop);}
               for(int i=7;i<=9;i++){
                    Integer opdruk=new Integer(i);
                    String text=opdruk.toString();
                    JButton knop=new JButton(text);
                    knop.addActionListener(luisteraar);
                         paneel2.add(knop);
               JButton ster=new JButton("*");
               JButton nul=new JButton("0");
               JButton hek=new JButton("#");
               ster.addActionListener(luisteraar);
               nul.addActionListener(luisteraar);
               hek.addActionListener(luisteraar);
               paneel2.add(ster);
               paneel2.add(nul);
               paneel2.add(hek);
               JPanel paneel3=new JPanel();
               JButton bel=new JButton("Bellen");
               JButton hangup=new JButton("Ophangen");
               bel.addActionListener(belluisteraar);
               paneel3.add("North",bel);
               paneel3.add("Center",hangup);
          p1.add("North",paneel1);
          p1.add("Center",paneel2);
          p1.add("South",paneel3);
     //alles wat met het antwoordapparaat te maken heeft
     JPanel p2 = new JPanel();
     kaarten.add(p1, TELEFOONKIEZER);
          kaarten.add(p2, ANTWOORDAPPARAAT);
          doos.add(kaarten, BorderLayout.CENTER);
//de itemlistener om van paneel te veranderen
public void itemStateChanged(ItemEvent event) {
CardLayout cl = (CardLayout)(kaarten.getLayout());
cl.show(kaarten, (String)event.getItem());
public static

Answer 1

By the way I get the mistake
Exception occurred during event dispatching:
java.lang.NoClassDefFoundError: javax/telephony/CallObserver
     at Test$belluister.actionPerformed(Test.java:35)
     at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1450)
     at javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(AbstractButton.java:1504)
     at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:378)
     at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:250)
     at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:216)
     at java.awt.Component.processMouseEvent(Component.java:3715)
     at java.awt.Component.processEvent(Component.java:3544)
     at java.awt.Container.processEvent(Container.java:1164)
     at java.awt.Component.dispatchEventImpl(Component.java:2593)
     at java.awt.Container.dispatchEventImpl(Container.java:1213)
     at java.awt.Component.dispatchEvent(Component.java:2497)
     at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:2451)
     at java.awt.LightweightDispatcher.processMouseEvent(Container.java:2216)
     at java.awt.LightweightDispatcher.dispatchEvent(Container.java:2125)
     at java.awt.Container.dispatchEventImpl(Container.java:1200)
     at java.awt.Component.dispatchEvent(Component.java:2497)
     at java.awt.EventQueue.dispatchEvent(EventQueue.java:339)
     at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:131)
     at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:98)
     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
     at java.awt.EventDispatchThread.run(EventDispatchThread.java:85)
Exception occurred during event dispatching:
java.lang.NoClassDefFoundError: javax/telephony/CallObserver
     at Test$belluister.actionPerformed(Test.java:35)
     at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1450)
     at javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(AbstractButton.java:1504)
     at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:378)
     at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:250)
     at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:216)
     at java.awt.Component.processMouseEvent(Component.java:3715)
     at java.awt.Component.processEvent(Component.java:3544)
     at java.awt.Container.processEvent(Container.java:1164)
     at java.awt.Component.dispatchEventImpl(Component.java:2593)
     at java.awt.Container.dispatchEventImpl(Container.java:1213)
     at java.awt.Component.dispatchEvent(Component.java:2497)
     at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:2451)
     at java.awt.LightweightDispatcher.processMouseEvent(Container.java:2216)
     at java.awt.LightweightDispatcher.dispatchEvent(Container.java:2125)
     at java.awt.Container.dispatchEventImpl(Container.java:1200)
     at java.awt.Component.dispatchEvent(Component.java:2497)
     at java.awt.EventQueue.dispatchEvent(EventQueue.java:339)
     at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:131)
     at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:98)
     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
     at java.awt.EventDispatchThread.run(EventDispatchThread.java:85)
why do I get this in my applet and not in my console application???
greetz,
olivier