hi,
Instead of writing Q3PopupMenu, just write QPopupMenu and try the code. That will work and also don't forget to write :
#include <qpopupmenu.h>

As far asthe examples in QT3 are concerned, no where it is mentioned as Q3PopupMenu. You can find the example in the following file:
<qt-directory>/examples/menu/menu.cpp

Please let me know the result.