If the columns are in a contiguous block then it's fairly easy. If the
columns are scattered around the sheet then it could be complicated.

--
Biff
Microsoft Excel MVP


"Ron" wrote in message
...
I have to record apt unit numbers in separate columns. I could up to 20 or
30
columns. My problem is apt unit numbers being entered multiple times. Is
there something that can check for duplicate numbers and let me know?

Thanks