Julie
It's kind of a long answer( I used the web address that was given, and it
walks you right through it, but like I say it looks like it only works on one
page). The question is about 10 below mine titled "Preventing Duplicate
Entries within a column"

Thanks, Pete

P.S. this is a copy and paste of one answer.

To highlight duplicates:
Select column A
From Format menu | Conditional Formatting
Formula Is: =COUNTIF($A:$A, $A1)1
Then format as Bold, or Red or whatever.



"JulieD" wrote:

Hi pete

might help if you copy & paste the "answer" you found ....

Cheers
JulieD

"pete" wrote in message
...
Sorry!

While I was waiting to see if my message posted, I looked at some of the
other questions to see if I could help someone else (not likely, but worth
a
try) I did find a previous question that was almost the same that was
answered. I tried it and it works on one worksheet. Can I get it to work
on
all 5 at the same time?

Thanks

"pete" wrote:

I have a spreadsheet that has 5 worksheets in it, that are purchase
ledgers.
(One for each week of the month). I would like to know if there is some
way
to have an error message pop up if someone enters a duplicate invoice
number
on any one of the 5 worksheets.

Thanks

Pete