Position changed

Last turn during my turn, Opponent used enemy controller last turn on my blue eye white dragon and switched to def.

During my turn, I switched blue eye to attack mode.

QUESTION: CAN I ATTACK WITH BLUE EYE?

This canada guy said: dude, you gotta read up the rulings, you cannot attack during the turn you change a monster's position to attack mode.

wtf? LOL rulel book says u cannot change the position of a monster that attacked, not attack with a monster that changed position o.o