java.lang.InstantiationException: Class not a MIDlet

[leiting]

i wrote a j2me application and when it runs it throws the following
error messages:
java.lang.InstantiationException: Class not a MIDlet
at com.sun.midp.midlet.MIDletState.createMIDlet(+51)
at com.sun.midp.midlet.Scheduler.schedule(+52)
at com.sun.midp.main.Main.runLocalClass(+28)
at com.sun.midp.main.Main.main(+116)

here is the code:
package test;

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

public class Test extends MIDlet{
public void startApp(){
//d.setCurrent(f);
}
public void pauseApp(){}
public void destroyApp(boolean p1){}

public void commandAction(Command comm, Displayable disp){

}
}

and my test.jad file's content:
MIDlet-Version: 1.0.0
MIDlet-Vendor: Midlet Suite Vendor
MIDlet-Jar-URL: test.jar
MicroEdition-Configuration: CLDC-1.1
MicroEdition-Profile: MIDP-2.0
MIDlet-1: Test,,test.Test
MIDlet-Name: test Midlet Suite

Anybody knows why there is an InstantiationException? Thanks in advance