how to giving the telephone number of a sms sender in j2me (WMA)

Question

I tried to give the sms number from Textmessage getAdress method but it return null. I use netbeans IDE.

receiver:

  ms=(MessageConnection)Connector.open("sms://:"+5000);


                    ms.setMessageListener(new MessageListener() {

                        public void notifyIncomingMessage(MessageConnection mc) {
                            try {
                                System.out.print("notify");
                                TextMessage mess=(TextMessage)ms.receive();
                                System.out.println(mess.getPayloadText());
                                System.out.print(mess.getAddress());//*********
                                ms.close();
                            } catch (IOException ex) {
                                ex.printStackTrace();
                            } 

                        }
                    });

sender:

  ms=(MessageConnection)Connector.open("sms://"+tf.getString()+":"+5000);
                TextMessage tm=(TextMessage)ms.newMessage(MessageConnection.TEXT_MESSAGE);
                tm.setPayloadText("salaaam maghsad jun");
                ms.send(tm);
                ms.close();

Sms is sent and I can read textmessage in server but I can't retrieve telephone number of sender with getAddress().
It returns null.