What does "used more than once" mean?

Does that mean entered into only one cell in a range of cells?

If that's the case you can use data validation for this.

Assume you enter the names in the range A1:A10 and you do not want any
duplicates.

Select the range A1:A10
Goto the menu DataValidation
Select Custom
Formula:

=COUNTIF(A$1:A$10,A1)<=1

Biff

"lorik" wrote in message
...
I need to have an error message occur if the same name is used more than
once
in that column. Is there a function or set of functions that I could use
to
do that?