>>Is there an easy way to handle that message ?
>
>Yes, by not having a duplicate primary key. You probably have an empty records some where and when creating your new records you have two same empty keys.

Maybe I have not been clear enough.

If i click on the NEW button in the toolbar to create a new instance of the field "classe" and i type "classeB" and click on the SAVE button, then if "classeb" does not exist in the table, it is saved.

However, if it does exist, i get the message "Uniqueness of index Classe is violated.

At this moment, i would like a message box telling "this value already exists. Try another one."

See what i mean ?

Thanks...