How to avoid duplicate invoice numbers?

[david]

I have excel for XP. I use it to store invoice number and information of my
customers. How do I avoid entering same invoice number of same customers?
Is there a function where I can set up Excel to warn me of duplicate
entries?

Thanks a lot for helping!

David

 

[Andy B]

David

You can do this using Data Validation.
By using the formula option and inputting:
=COUNTIF(A2,$A$2:$A$1000)>1 and filling this down the column you can get
Excel to display an error message of your choice.

Andy.

 

[JMay]

=COUNTIF(A2,$A$2:$A$1000)>1

I thought it was:

=COUNTIF($A$2:$A$1000,A2)>1

???

 

[Andy B]

J

Yep. I'll give you that one!! <g>

Andy.

=COUNTIF(A2,$A$2:$A$1000)>1

I thought it was:

=COUNTIF($A$2:$A$1000,A2)>1

???

 

[david]

Thanks guys for all your help. Something to explore more. Is there a
formula that will let me goto that duplicate invoice number automatically?

Thanks again!

David

 

[Andy B]

David

Not that I can think of, without VB, because Excel won't actually let you
come out of the cell until it satisfies the criteria. There's nothing to
stop you doing a Ctrl-F (find) once you've come out of the cell, though.

Andy.