Max ( // put your calculation expression here ; 0 )
If(your calculation< 0;0;your calculation)
Thanks for your help guys. I've used Phil's formula, and it does keep the calculation result from going below 0, (zero). I'll try Rick's next to see what the difference is.
Next step...When the calculation result is LESS than zero, how do I set an error message to pop-up and undo the last date entry?
Thanks again for your help.
Rick's method should produce identical results. I like mine because I only have to enter the calculation expression once.
Don't use either method if you instead want to trap for this error and put up an error message. Instead, open Manage | Database | Fields, Change the field to a number field with an auto entered calculation and then select the Validation tab.
Set a validation calculation such as Self > 0. You can keep the standard validation error message or type in your own. You can also choose whether users can override the error or not.