Read this requirement carefully:
Write a trigger writes lines to an audit table ONLY WHEN THE RM00101 CUSTNMBR OR CUSTNAME CHANGES
If you've ever written a trigger on RM00101 (or any Dynamics GP table) you know that ALL fields are updated when you save in GP, even if the data is not changed.
In the past, I've compared the field in the DELETED table to the field in the INSERTED table, but that gets wordy and is not... elegant.
I have a solution