Hi,

I have FORM A with a field "SIM" that is linked to the field "SIM" in FORM B. 

The challenge: A "SIM" record in FORM-B can only be used/linked ONCE in a single record in FORM-A, since lookup fields cannot be marked with "no duplicates" I would like to restrict the lookup field in FORM-A to only show records that have NOT been used before (or that basically are "available").

I suppose this needs to be done in a workflow function "on create/edit", what is the appropiate Deluge code for this?

Thank you!