Not sure I'm following comletely correctly, but perhaps this is what you
seek:

IIf(Len(tblInvoice.ClientDetail & "") = 0, IIf(Len(tblInvoice.HorseName &
"") = 0, funGetHorseName(tblInvoice.InvoiceID, tblInvoice.HorseID),
tblInvoice.HorseName), tblInvoice.ClientDetail)

--

Ken Snell
http://www.accessmvp.com/KDSnell/


"Bob Vance" wrote in message
...
What I want is tblInvoice.ClientDetail but if blank tblInvoice.HorseName
but if blank
funGetHorseName(tblInvoice.InvoiceID,tblInvoice.Ho rseID),tblInvoice.HorseName)

& "iif(tblInvoice.ClientDetail='',tblInvoice.HorseNa me='
',funGetHorseName(tblInvoice.InvoiceID,tblInvoice. HorseID),tblInvoice.HorseName)
AS ClientDetail," _

--
Thanks in advance for any help with this......Bob
MS Access 2007 accdb
Windows XP Home Edition Ver 5.1 Service Pack 3