Limiting entry in text entry fields

Hi!

I've got a calculator that uses triggers based on variables to calculate a grade level. I'd like to simplify data entry for my user. I'm thinking I'd like to use a drop-down list for the text entry, or limit the format the text entry field will accept.  Currently the user has to enter #-#, but I suspect I'll get different formats. 

Alternatively, I suppose I could write additional conditions using an OR operator, but I had trouble making that work.

Anybody have any thoughts on how to make it easier?

3 Replies