Erro no codigo

import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Form;
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;

/**
 * This class is used to test basic execution of MIDLet HelloWorld.
 * 
 * @author Alcides Flach
 * 
 * @see javax.microedition.midlet.MIDlet
 */
public class HelloWorld extends MIDlet implements CommandListener {

	private Display display;

	private Form form;

	private Command exit;

	/**
	 * Create an instance of the MIDlet HelloWorld.
	 */
	public HelloWorld() {
		// call the super class constructor		
		super();

		// create a command to finish the application
		exit = new Command("EXIT", Command.EXIT, 1);

		// create a form object
		form = new Form("J2ME Testing");

		// append the messege
		form.append("Hello World!");

		// add the command
		form.addCommand(exit);

		// set the form to listen the events
		form.setCommandListener(this);
	}

	protected void startApp() throws MIDletStateChangeException {
		// get the display instace of this MIDlet
		display = Display.getDisplay(this);

		// set the form object visible on the display
		display.setCurrent(form);
	}

	public void commandAction(Command c, Displayable d) {
		// verify if the command event is the exit command
		if (c == exit) {
			try {

				// signals the MIDlet to terminate and enter the Destroyed state
				destroyApp(false);
			} catch (MIDletStateChangeException e) {
				e.printStackTrace();
			}

			// notify the application management software that it has entered
			// into the Destroyed state
			notifyDestroyed();
		}
	}

	protected void pauseApp() {
	}

	protected void destroyApp(boolean arg0) throws MIDletStateChangeException {
	}
}