Does it help if you set "APDivisionNo$" before setting "VendorNo$"?

Thank you thank you thank you! Can't believe it was that easy but glad that it was. Is there somewhere I can learn about little tricks like this?

Glad it worked. All of the "little tricks" I know just come from experience.

Do you happen to know what the command is to launch a UI via BOI? I am trying to launch the PO screen after my code completes but have been unable to find the actual command. It looks like at one point it was nprocess() but that doesn't seem to work in version 5 (Sage 100 ERP 2013)

I never did like nProcess() because the UI looks different when you run things that way. There is also oSession.nInvokeProgram(programName, recordKey). So, in your case, oSession.nInvokeProgram("PO_PurchaseOrder_ui", newPONum)

The difference is that nProcess() blocks - meaning that the script halts until the user has closed the UI window. nInvokeProgram() runs the UI in a separate process, so your script will finish without waiting for the UI to close.