Try

=IF(OR(A1="",B1=""),"",A1+B1)


--
Cordially,
Chip Pearson
Microsoft MVP - Excel
Pearson Software Consulting, LLC
www.cpearson.com




"bayanbaru" wrote in
message
...
My formula is C1=SUM(A1: B1). I want to use IF function. If A1
and B1 is
blank C1 should be blank. Right now it show C1=0