I have rows of data that contain a column with an invoice number, if I am
entering a duplicate invoice number, I want to be alerted. I want to be
allowed to enter duplicates, but I want Excel to somehow alert me that it is
a duplicate so I can check it. What is a good way to do this?
--
KKD

For alert only you could use Conditional Formatting to highlight duplicated
numbers.

Both instances will be highlighted.

In FormatCFFormula is: =COUNTIF($A$1:$A$50,A1)<1

Format to a color and OK

If you wanted to PREVENT duplicates you would enter this formula in Data
ValidationAllowCustom

=COUNTIF($A$1:$A$50,A1)=1


Gord Dibben MS Excel MVP

On Wed, 27 May 2009 14:36:11 -0700, KKD
wrote:

I have rows of data that contain a column with an invoice number, if I am
entering a duplicate invoice number, I want to be alerted. I want to be
allowed to enter duplicates, but I want Excel to somehow alert me that it is
a duplicate so I can check it. What is a good way to do this?

One easy monitor/alert is to use a formula in an an adjacent col
Assume you are entering data in A2 down
Put in B2: =IF(COUNTIF(A$2:A2,A2)1,"<<Dup !","")
Copy down to cover the max expected extent of data in col A
Col B will give you the necessary visual alerts

Works ok? Click the YES button below
--
Max
Singapore
http://savefile.com/projects/236895
Downloads:25,000 Files:300 Subscribers:70
xdemechanik
---
"KKD" wrote:
I have rows of data that contain a column with an invoice number, if I am
entering a duplicate invoice number, I want to be alerted. I want to be
allowed to enter duplicates, but I want Excel to somehow alert me that it is
a duplicate so I can check it. What is a good way to do this?
--
KKD