Make sequential numbers each time sheet is opened

I would like to have a cell reflect a sequential number each time this
spreadsheet is opened. It will be a purchase order sheet and will be on a
server and accessed by several users. I guess it is similar to invoice
numbers so if you have any thoughts on control issues that would be
appreciated as well.
Thank you very much,
Darrell

See

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

In article <dj3ocj$2d4r$1@news3.infoave.net>,
"Darrell Shuman" <dshuman@specializedstructures.com> wrote:

> I would like to have a cell reflect a sequential number each time this
> spreadsheet is opened. It will be a purchase order sheet and will be on a
> server and accessed by several users. I guess it is similar to invoice
> numbers so if you have any thoughts on control issues that would be
> appreciated as well.
> Thank you very much,
> Darrell