=IF(C1=",A1,A1&B1)

--

HTH

RP
(remove nothere from the email address if mailing direct)


"Jack" wrote in message
...
Hello. I have worksheet in which I have data in the A column, data in the
B
column, and (sometimes) in the C column. I'm having trouble with the
correct
formula. I want to put in the D column something that states If "C1" is
blank then enter A1. And If "C1" is not blank, then concatenate A1 and
B1.

I hope that makes sense and thank you in advance.