Latihan J2ME Radio

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

public class Midlet_3 extends MIDlet implements CommandListener{

private Display display;
private Command cmdKeluar, cmdDaftar, cmdKembali, cmdSubmit;
private Form form;
private TextField nama, alamat, no_telp;
private Alert alert;
private ChoiceGroup jSpeedy;


public Midlet_3(){
   
    display = Display.getDisplay(this);

    //membuat form
    form = new Form("Form Pendaftaran");

    //menambahkan teks kedalam form
    form.append("Selamat datang di TelkomSpeedy");
   
    //membuat dua buah command, "Keluar" dan "Daftar"
    cmdKeluar = new Command("Keluar", Command.EXIT,1);
    cmdDaftar = new Command("Daftar", Command.SCREEN,1);
    cmdSubmit = new Command("Submit", Command.SCREEN,2);

    //menambahkan command kedalam form
    form.addCommand(cmdKeluar);
    form.addCommand(cmdDaftar);
    form.setCommandListener(this);
}

public void startApp(){display.setCurrent(form);}
public void pauseApp(){}
public void destroyApp(boolean unconditional){}

private void form(){
    form = new Form("Form Pendaftaran");
    nama = new TextField("Nama: ", null, 35, TextField.ANY);
    alamat = new TextField("Alamat: ", null, 50, TextField.ANY);
    no_telp = new TextField("Telepon:", null, 25, TextField.PHONENUMBER);

    jSpeedy = new ChoiceGroup("Speedy", Choice.EXCLUSIVE);
    jSpeedy.append("Family", null);
    jSpeedy.append("Bisnis", null);
    jSpeedy.append("Executive", null);
   
    //menambahkan append ke dalam form
    form.append(nama);
    form.append(alamat);
    form.append(no_telp);
    form.append(jSpeedy);

    //menambahkan command ke dalam form
    form.addCommand(cmdKeluar);
    form.addCommand(cmdSubmit);
    form.setCommandListener(this);
   
    //menampilan form
    display.setCurrent(form);
}

public void commandAction(Command c, Displayable s){
    if(c == cmdKeluar){
        destroyApp(false);
        notifyDestroyed();
    } else if (c==cmdDaftar){
        form();
    } else if (c==cmdSubmit) {
        int indexs = jSpeedy.getSelectedIndex();
        Alert info = new Alert("Informasi");
        info.setType(AlertType.INFO);
        String teks = null;
        teks = nama.getString();
        info.setString("Terima Kasih : \"" +teks+ "\" dengan berlanggangan paket " + jSpeedy.getString(indexs) + "\" Sudah Mendaftar");
        info.setTimeout(Alert.FOREVER);
        display.setCurrent(info);
    }
  }
}