Use Transaction Notification in Approval Procedures

Hi

I want to use the "SBO_SP_TransactionNotification" Stored procedure in one of my approval procedures. I have implemented a approval procedure based on certain criteria when a "PURCHASE ORDER" is created. Now i want to send an email out to certain users when a approval is needed for a PO.

I m not sure if transaction Notification is being used when Approval procedure are involved. For all POs that does not require an approval , my code for emailing uses in the SP is working fine.

Has anybody came across this scenario? pls help.

thanks

raghu