First of all, we already know how to examine $HTTP_POST_VARS, we know how to name form inputs in such a way that they will be presented as a nice PHP array. We've read Richard Creech's article on making a form's controls dynamic. Why do we need anything else at this stage?
Let me explain. You see, I have a Delphi background and with Delphi you get very much addicted to re-using instead of re-inventing. So, if you find yourself coding something that gives you this dejavu - “I've been doing this before” - you want to invent a class that can be reused throughout your projects.