Stuck on Page 10!

I'm currently working through the book going line by line trying to build the Alien Attack project.

I'm now to page 10, where the book explains an if statement with InputManager.ControlState.Start

My compiler is throwing "The name 'InputManager' does not exsist in the current context.

I believe this means I don't have the correct using statements, but the book only lists Xna.Framework, Xna.Framework.Graphics, and Xna.Framework.Content;  I've tried adding Xna.Framework.Input and it's still a no go, google isn't being much help either.

Any clues as to what I'm doing wrong?  I'm comparing against the source provided and not seeing a difference at this early stage.  I think I'm missing the forest for the trees...

I replied via email but I want to reply here as well in case anyone else runs into the same issue:

Have you read and implemented through page 15?  The InputManager is briefly mentioned on page 10, but we don't actually write it until the next section.  Until the class is added to the project and implemented as discussed on pages 12-15, you will get compilation errors.

AH HAH! That would make sense. So I'm just being overly anal too soon.

That's what happens when you get an IT guy who dabbels in programming reading your stuff.