Hi all, 

I've got two custom modules that both contain lookups:

1) "Customers" module, with a lookup field 'Unit' referencing "Units" Module

2) "Units" module, with a lookup field 'Current Occupant' that would change automatically based on the function.

What i'm trying to accomplish is that whenever a 'Unit' is referenced in the lookup field in the "Customers" module, I want the relevant 'Unit' to then reference that "Customer" in the 'Current Occupant' lookup field. 

Does anyone have any advice for the code I need for this as I cannot get anything to work?