How do I get to regi.?

For Regirock in white 2 you need to go into clay tunnel and wander around eventualy you will come to a door on the right side that will take you to a secret room and in that room there will be a door with an eye in front of it stand on the center of the eye and walk down 6 spaces and right 8 or 9 spaces and hit a the screen will say that there is an old button there say yes to step on it and the screen will go dark. When the screen comes back on go to the mystry door and go in go to the back chamber and regirock will be standing there save before attacking him so that if you feint him you can just turn off the power and try again

Which Regi? There are four (Regirock, Regice, Registeel, and Regigigas). You need to be specific.