I have a form that asks questions of the user, and I would like to assign a "score" to their answers behind the scenes.  For example, I have a drop down field called "Licensing" that asks for the users license type and then there is a drop down with the following selections: N/A, Med 1, Med 2, or Med 3.  I would like the following scores to be assigned to their answer:  N/A  = 0, Med 1 = 1, Med 2 = 2, Med 3 = 3.  What kind of formula will work for me?

Thanks