>I work we free tables
>Is it possible to use candidate keys ?
Yes it is.
BUT!!!
BUT!!!
(BUT several times)
If you have APPEND BLANK in the Init of the form your application will crash very easily.
Imagine that two (or more) user open that form at the same time. Candidate jey will rise an error immediately.
NEVER use APPEND BLANK in the init of the form. Insert records AFTER the user confirm it and YOU validate that record.
Against Stupidity the Gods themselves Contend in Vain - Johann Christoph Friedrich von Schiller
The only thing normal about database guys is their tables.