Java Tutorial/J2ME/RadioButton

RadioButton with ChoiceGroup

import javax.microedition.lcdui.Choice;
import javax.microedition.lcdui.ChoiceGroup;
import javax.microedition.lcdui.rumand;
import javax.microedition.lcdui.rumandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.StringItem;
import javax.microedition.midlet.MIDlet;
public class J2MERadioButtons1 extends MIDlet implements CommandListener {
  private Display display;
  private Form form = new Form("Gender");
  private Command exit = new Command("Exit", Command.EXIT, 1);
  private Command process = new Command("Process", Command.SCREEN, 2);
  private ChoiceGroup gender = new ChoiceGroup("Enter Gender", Choice.EXCLUSIVE);
  private int currentIndex;
  private int genderIndex;
  public J2MERadioButtons1() {
    display = Display.getDisplay(this);
    gender.append("Female", null);
    currentIndex = gender.append("Male ", null);
    gender.setSelectedIndex(currentIndex, true);
    genderIndex = form.append(gender);
    form.addCommand(exit);
    form.addCommand(process);
    form.setCommandListener(this);
  }
  public void startApp() {
    display.setCurrent(form);
  }
  public void pauseApp() {
  }
  public void destroyApp(boolean unconditional) {
  }
  public void commandAction(Command command, Displayable displayable) {
    if (command == exit) {
      destroyApp(false);
      notifyDestroyed();
    } else if (command == process) {
      currentIndex = gender.getSelectedIndex();
      StringItem message = new StringItem("Gender: ", gender.getString(currentIndex));
      form.append(message);
      form.delete(genderIndex);
      form.removeCommand(process);
    }
  }
}