Let me clarify to make sure I'm asking the right question.
The serial number does not change, only the information pertaining to it. i.e. On "Customers" table I have:
On my "Jobs" table I have
Customer_ID "connected via relationship"
On the "Jobs" table, when I type in a serial number for a corresponding customer, it auto fills the rest of their information. I need to be able to create records in "Customers" from within the "Jobs" table, so I have it setup to allow for that in the relationship. The problem is if the "Customer_ID" has an existing number in it and I type in any other cell related to it, it will change the corresponding info related to that serial number.
So I just looked up Customer_ID "1"
Customer_name "John Smith"
Customer_Phone "(555) 999-5212"
Customer_Address "1212 Cherry Blossom St"
Now I want to add a new customer. If I don't delete the serial from the look-up cell before entering data into the other customer info cells it will change the data related to Customer_ID "1" instead of creating a new record.
Did I explain that right? Everything seems to be working according to how it should be. I think I may just need a script or something along those lines to keep from losing existing records but still have the ability to both look-up info and create records from the "Jobs" table.
I suggest a button labeled "New customer" or such with a script along the following lines:
Go To Layout [Customers (customers)]
Set variable [$CustID ; Customers :: Customer_ID]
Go To Layout [original layout]
Set Field [Jobs :: Customer_ID ; $CustID]