Sample Form Singleton

import javax.microedition.lcdui.Alert;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.TextField;


public class RFIDVerificationForm extends CustomForm {

    private TextField txtRFIDNo = null;
    private Command cmdVerify = null;
    private Command cmdBack = null;

    private static RFIDVerificationForm thisForm;
    private static RFIDVerificationFormListener listener;

    public RFIDVerificationForm() {
        super();
        thisForm = this;
        initComponents();
        addComponents();
    }

    protected void initComponents() {

        txtRFIDNo = new TextField("Enter RFID No", "", 20, TextField.ANY);
        cmdVerify = new Command("OK", Command.ITEM, 1);
        cmdBack = new Command("Back", Command.BACK, 1);

    }

    protected void addComponents() {

        append(txtRFIDNo);
        addCommand(cmdVerify);
        addCommand(cmdBack);
        setCommandListener(getListener());
    }

    private RFIDVerificationFormListener getListener() {
        if (listener == null) {
                listener = new RFIDVerificationFormListener();
        }
        return listener;
    }

    public static RFIDVerificationForm getInstance() {

        if (thisForm == null) {
                thisForm = new RFIDVerificationForm();
        }
        thisForm.txtRFIDNo.setString("");
        return thisForm;
    }

    private class RFIDVerificationFormListener implements CommandListener {
        public void commandAction(Command cmd, Displayable displayable) {

            if (cmd.getLabel().equals("Back")) {
                thisForm.prevForm.setAsDisplay();
            }
            else if (cmd.getLabel().equals("OK")) {                   
               
           }
        }
    }
}