To help prevent accidential copying and pasting over
Validation cells, you could employ this technique from J.
Walkenbach:

http://j-walk.com/ss/excel/tips/tip98.htm

HTH
Jason
Atlanta, GA

-----Original Message-----
Remember that Validation can be overwritten easily with
copy/paste:

http://www.contextures.com/xlDataVal07.html#Unique

HTH
Jason
Atlanta, GA

-----Original Message-----
I would like to use a column to identity each row in a
list as a separate
item #. I can't have duplicates in this column and
would like the program to
prevent someone from entering an ID# in twice. Any
ideas?
.

.