I created a custom tab with two attributes for Customer. The first is the Customer_id in order to link my custom tab to the master data.

Now when adding/updating a value there, it saves the value for the master linked and this is the behavior that I need (so far all is OK)

But if the user click on the (+) button instead of update directly the existing value in the field ‘New cf Jfo 2’, a new line is saved in the database but will be never visible because a first value exists.

How to avoid this behavior ? How to avoid the  user to create a new value when a first already exists ?

Thank you

Jean-Louis