مشكلة مع أول مشروع لي

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
public class HelloWorld extends MIDlet implements CommandListener
{
private Display display;
private TextBox textBox;
private Command quitCommand;
public void startApp()
{
display = Display.getDisplay(this);
quitCommand = new Command("Quit", Command.SCREEN, 1);
textBox = new TextBox("Hello World", "My first MIDlet", 40, 0);
textBox .addCommand(quitCommand);
textBox .setCommandListener(this);
display .setCurrent(textBox );
}
public void pauseApp()
{
}
public void destroyApp(boolean unconditional)
{
}
public void commandAction(Command choice, Displayable displayable)
{
if (choice == quitCommand)
{
destroyApp(false);
notifyDestroyed();
}
}
}

package greeting;