I am new to filemaker, I have two fields and need to insure field a is greater than field b. If it is less that b I need to keep a blank and display an error message saying it must be greater than b.

In the Validation tab of the field options, use a calculation to validate:

FieldA > FieldB

Then add a custom message if validation fails (at the bottom of the Validation tab.)

You might need to allow one of the fields to be empty, to avoid the validation message after only field has been entered:

FieldA > FieldB or isempty(FieldA)

Thanks you for the help I still need some guidance so let me give you a better example. I have 6 fields,

Perpetual Start

Perpetual Stop

Total Footage

Footage Used

Field Validation

Error Message

(Footage Used) is a calculation [Prep Stop - Perp Start].

If (Total Footage) is greater than (Footage Used) I would like some type of error message. I created a script that works,

If Field Validation = 0

Beep

Show Message