Allow entry in only one field

[moon0129]

Although it seems like it should be really easy I cannot figure out how to do this. I am creating a time tracking system and I will like to set each time entry to be related to either a Job or a Task, but never both. On my layout I have two pop-up menus, one with Job#'s and one with Task#'s. I would like to be able to select either or, but it I select both a validation message occurs. I am very new to FMP, so this is probably not that difficult.

I have tried several options by validating data through a calcuation, but I think I am just doing it wrong.

my job field is: tim.job# and my task field is tim.task#

I assume that I need to have a validation calculation set for each field, but what does it need to be? Maybe there is function that I just don't know about. I have been trying with IsValid and IsEmpty.

[comment]

Try:

IsEmpty ( tim.job# ) or IsEmpty ( tim.task# )

[moon0129]

Thanks, it worked, and it makes a lot of sense now that I think about it....

I knew it was suppose to be easy.