Thank you for the reply, but the problem does not solve by having a manual numbering. How to separate the two types of purchases - for example Goods and Service?
Different buyers are there for material and service purchase and with manual numbering we cannot maintain a sequential series for each type of purchase.
If you want different number for Goods and Service, you to do Manual Entry Only.
I'm wondering if you could achieve this using personalization....You would have to maintain/create your own sequences and then when a new PO is saved you could use personalization to populate the PO number based on the Goods/Services value (or whatever you choose to use for your logic to determine which sequence to increment). The tricky part I see would be getting the right trigger so it only fires on new records, and if the users saved the record before any line information were entered...and what if they did a PO that had BOTH values in it? (Maybe doesn't make sense business-wise, but system-wise it's possible)