null pointer exception in lwuit

i am using netbeans ide 6.9 to develop mobile application but i am not able to acess resource file like theme.res from res folder of my project. i.e while running its giving the error as below
startApp threw an Exception
java.lang.NullPointerException
java.lang.NullPointerException
at com.sun.lwuit.plaf.UIManager.buildTheme(+1)
at com.sun.lwuit.plaf.UIManager.setThemePropsImpl(UIM anager.java:377)
at com.sun.lwuit.plaf.UIManager.setThemeProps(UIManag er.java:353)
at MenuItem1.startApp(MenuItem1.java:37)
at javax.microedition.midlet.MIDletProxy.startApp(+7)
at com.sun.midp.midlet.Scheduler.schedule(+270)
at com.sun.midp.main.Main.runLocalClass(+28)
at com.sun.midp.main.Main.main(+80)
can any one help me wat is the problem.

how are u accessing theme.res from your res folder??...
paste the code...probably you are trying "/theme.res"..!!