Update table with data from another table via form (1 Viewer)

This seemed like a remarkably simple problem at first but.........have recently become confused. I have a basic automotive service DB with multiple tables. The main table is the vehicles table with co. vehicles, drivers and other vehicle info (PK is the Vehicle #.) I also have a service table with typical services - lube, oil, and filter, transmission service, brake job, and other misc. goodies (PK = Service ID SK=Vehicle#.) The third table consists of prices for each service (PK=Service Price ID SK= Service ID.) I'm trying to create some way of having the user click on a service and have the service and price be entered into a subform on the vehicle subform. Any solutions?

Solution Found

For anyone looking for a solution to this or similar problems I have found a thread which will help. Do a search for "Auto Fill based on Combo Box" without the quotes. This is a found in the Forms section and will either solve the problem or lead to a solution.
Thanks!!!