search for: inputvalid

i just started to work with ROR, and made a form with scaffolding. I achieved to add some extra inputvalidation but i also want to add some code that changes some specific textfields with the .titlecase / .titleize and then stores it to the database. I had to add the validation code to the model file, is this also the place to add the titlecase ? the columname of the regarding textfield is last_name...