CJRolls:

Believe you've changed your specs in your response <g

Couldn't help but feel that what you're looking for
is a simple auto-row numbering in col A
which appears "blank" until something is entered in col B

In which case, think we could also place in A1:
=IF(B1="","",ROWS($A$1:A1))
and copy A1 down as far as required

--
Max
Singapore
http://savefile.com/projects/236895
xdemechanik
---