Using Keynote, can you get the keyboard (not external) so you can use B for Black?

[oboedot]

I am presenting using Keynote next week. I have a presentation where I would like to use B for Black or W for white to turn off the display when the iPad isn't being used. From what I can see, you can do this with a keyboard while in Keynote. Must it be an external keyboard, or can I get the iPad keyboard to display right on the iPad 2? Thanks