I said data validation (DataValidation), not conditional formatting. Use a
type of custom with that formula and you will see an error on input.

--
HTH

Bob

(there's no email, no snail mail, but somewhere should be gmail in my addy)

"tankerman" wrote in message
...
Bob that works fine and I am able to notice the entry duplicate by the
background change but our tickets are in a desending order 8 characters
long.
Is there anyway that once the number is entered that if it matches a
previously entered number that it won't accept it or notify the person
entering the info that this number has already been entered.

"Bob Phillips" wrote:

Trap it on input by adding data validation to those cells with a formula
like

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

--
HTH

Bob

(there's no email, no snail mail, but somewhere should be gmail in my
addy)

"tankerman" wrote in message
...
I have a worksheet that several people enter info onto my problem is
that
some of the info gets duplicated and causes a miscount in the numbers,
I
have
to go back and track down the duplicate entries and delete them. I have
column headers like this
TICKET# PRODUCT TANK# LOADER STARTTIME

and several other heading. The ticket# is a unique non duplicating, is
there
anyway I can get the workbook to not accept a TICKET# that has already
been
entered in previously in the worksheet.