I'm sure this is an extremely basic question to most of you, but i am extremely new to filemaker (I'm creating my first file). Anyway, what I want to do is have a validation in one of the fields so when you type a number in it, it has to be equal to or less than another field. In other words, I have a list of a card collection that I am selling. I have a column for the name, type, # of cards, value, ect. I have another field for when someone wants to buy a card, obviously they can't buy more cards than what I have, ergo, the field must be equal to or less than the number of cards I have. I would appreciate any help. Thanks.