I have a formula very simple in 2000 columns.

A B C
1 5 3 =IF(B3-A5=0, "ORDER COMPLETE")

It works pretty nice, but i have the formula copied in 2000 columns. Even if
i don't write down any data, the column C is giving me the message because i
haven't entered information for A and B, so C recognices a zero as a result.
As a consequence, the phrase ORDER COMPLETE, shows in the rest of the 2000
columns. How can i get that message only when it is 0 zero by entering data
only to A and B