In MS Access 2003, how can I use a dropdown list as the popup form of a parameter query?

I have a parameter query that prompts users to type in criteria stored as a lookup box in a table, e.g. for each record, the user has selected “Observation,” “Treatment,” or “Diagnostics.” The query prompts for users to manually type which of these three types of records they want to view. Is there a way (pref w/out code) to give them a dropdown box listing the three choices so they don’t get “typer’s cramp” (or like me, type too fast and keep misspelling the word so that the report doesn’t run right)? I am using MS Access 2003. I am a newbie, so if answering w/code, make it slow and simple. Thx!