WarioWare: Twisted! How to jump in Wario-Man boss stage

Finally I get original WarioWare: Twisted! game cartridge for my Game Boy Advance
Today I tried to beat final boss (Wario-Man) and faced with some troubles when start jumping with my GBA (for beating last boss I need to do Mambo dance by repeating movies)... And I failed, because jumping with gameboy did not work at all.
So, there is a answer for the question "How to jump in final boss stage?":
JUST PRESS "A" BUTTON
:-)