Where to start on a Wrod Drop game

I want to make a simple word drop game but Im not sure the best place to start.
My idea is to have a series of frames, each with a different key word that drops, along with some random "junk" words.
I want the user to be able to type in the word and hit enter before the word hits ground. I figure this will only take a few "if else" statements and a hit test to check if the word has touched ground. what I don't know is how to evaluate the contents of a text box. Also I want a point counter. I'm pretty sure i can make it work, but will a point counter work when you are advancing frames? Anyone have advice on where this?
Mostly I need to know how to eval a text box though.

Many thanks

Mark