Chip Pearson tells us he
http://www.cpearson.com/excel/NoDupEntry.htm
************
Hope it helps!
Anne Troy
www.OfficeArticles.com

"Joe" wrote in message
...
I am using excel as a small database. I want to know how to protect a colum
from having the same entry posted twice. Example: If cell A1 contains the
number 1001 how can I get a warning or prevent that same number from being
entered in say cell A500. Thanks
--
Joe