need an error msge when I attempt to enter a duplicate value in a

I am entering unique serial no. in col A. Can I set up a rule which will not
allow a duplicate serial no. entry into another cell?

If you put a Custom Data Validation as follows:-

=IF(MATCH(A1,A:A,0)<>ROW(A1),FALSE,TRUE)

This assumes that you are putting the serial number in column A, adjust accordingly if this is not the case

See

http://cpearson.com/excel/NoDupEntry.htm

In article <[email protected]>,
"pg23673" <[email protected]> wrote:

> I am entering unique serial no. in col A. Can I set up a rule which will not
> allow a duplicate serial no. entry into another cell?

Check out the validation in the Data section.
select the area of interest (A:A)
<data><validation><Settings><Custom>
enter =countif(A:A,A1)=1

Set the error alert as you want it


"pg23673" wrote:

> I am entering unique serial no. in col A. Can I set up a rule which will not
> allow a duplicate serial no. entry into another cell?

Chip Pearson has something that can help:
http://www.cpearson.com/excel/NoDupEntry.htm



pg23673 wrote:
>
> I am entering unique serial no. in col A. Can I set up a rule which will not
> allow a duplicate serial no. entry into another cell?

--

Dave Peterson

Thanks for the help guys.

"Gary Brown" wrote:

>
> If you put a Custom Data Validation as follows:-
>
> =IF(MATCH(A1,A:A,0)<>ROW(A1),FALSE,TRUE)
>
> This assumes that you are putting the serial number in column A, adjust
> accordingly if this is not the case
>
>
> --
> Gary Brown
> ------------------------------------------------------------------------
> Gary Brown's Profile: http://www.excelforum.com/member.php...o&userid=17084
> View this thread: http://www.excelforum.com/showthread...hreadid=378030
>
>