Setting a "trigger" for lookups
I have upgraded from version 2 to 7. In 2, lookups were easy : I could specify the trigger field in one record (eg invoice number) to automatically import data into various other fields from a record with the same invoice number in a different file. How do I do that in this more sophisticated version? I.e. enter an invoice number and have all of the other information dragged over? I've connected all of the target fields between the two files in the relationships table but how do I set the one critical trigger field to link specific records?