Adobe Sign validation on two date fields

Hi,

In my Adobe Sign document, I need to validate that last job date is not greater than current job date.  Is this possible through a custom validation?

The validation logic would be something like this: if lastJobDate > currentJobDate, message "Last Job Date cannot be greater than Current Job Date".

Is this possible at the text tag level or is there some kind of form level validation.

Any help is greatly appreciated.

Richard