[texhax] Defining bullets in beamer presentation

[Petar Milin]

Hello!
I am trying to change bullets in my presentation (beamer). I use this, 
as advised, but I only get errors:

\renewcommand\labelitemi{\includegraphics[width=0.3in]{backbulls/BULETT_01.GIF}}
\renewcommand\labelitemii{\includegraphics[width=0.3in]{backbulls/BULETT_02.GIF}}

...
! LaTeX Error: \labelitemi undefined.
...

Thanks,
Petar