Any chance that those existing workbooks have a name called Markup?

Insert|Name|define to check

or Jan Karel Pieterse's (with Charles Williams and Matthew Henson) Name Manager:
NameManager.Zip from http://www.oaltd.co.uk/mvp

Samad wrote:

I put some vb code to a add-ins file that create markup i.e

Function markup(principal, rate, days)
markup = principal * rate / 365 * days

End Function

it works fine in new sheets but whenever I try to replace the formulas in
existing sheets it display #name? error.
can someone help me what I'm doing wrong or is it a formatting problem

Thanks in advance

--

Dave Peterson