ritarowe, here is one way to do it, put in workbook open code

Sheets("Sheet1").Range("A1").Value = _

Sheets("Sheet1").Range("A1").Value + 1



If this is a temple have a look here for other ways to do it



http://www.mcgimpsey.com/excel/udfs/sequentialnums.html
--
Paul B
Always backup your data before trying something new
Please post any response to the newsgroups so others can benefit from it
Feedback on answers is always appreciated!
Using Excel 2002 & 2003


"ritarowe" wrote in message
...
I have a purchase order spreasheet working with. I would like it to
automatically generate a unique identifier (PO number) upon opening the
file;
is this possible? or some formula to automatically pull in the next
sequential #?