Hi Arsen,

See J.E. McGimpsey's Sequential Numbers page:

http://www.mcgimpsey.com/excel/udfs/sequentialnums.html


---
Regards,
Norman


"Arsen" wrote in message
...
I am using Excel to create invoices. I need to uniquely identify each
invoice
with an invoice number. Is there a way of generating a serial number
sequentially in each worksheet