Long time no problems, Rita!
If "D" didn't boot you into AHT it sounds like it ought to be on one of the discs that came with your MBP, but since it apparently shipped with Mt. Lion, apparently not; did you look for the referenced disc?
I believe this is dependent on which version of OS X your MBP shipped with rather than which version it's running.
If it's not on a disc, "D" or command-D ought to get you to a dropdown with a list of all available networks from which you choose yours and enter your password as prompted, but that doesn't sound like what you're seeing.
Too bad you can't take a screenshot.
Why don't you try again, but with command-D this time?