I'm not sure how to word this, but I'll try my best. I need a way to setup an interface so that the user can create it's own equation.

This is what I need:

Field 1: Name of equation

Field 2: First entry - beginning price

Field 3: Second entry - ending price

Field 4: Fee Entry

Name of equation [Field 1], if price < [field 2] but > [field 3] charge this amount [field 4].

Is there a way that I could set this up so that the user can enter these fields and create their own equations? So that at a later time they can select the name and have the equation already setup and run by itself.

Easily, not to my knowledge. Calculations aren't even second-class in FMP, let alone first-class. As a guy whose been using systems with first class equations for years, I feel your pain.

But, it is possible! You'll just need to build your own expression parser/evaluator to handle anything your user might put in those fields.

Unless some of your "equations" are a lot more coplex than what looks like the discount calculation, you don't need to edit equations to accomplish what you need. These are easily setup with lookups and/or relationships and a table of values. How?, not nearly enough information from your description.

-bd