set up a column in excel with unique entries

[Guest]

How does one create a column to accept only unique serial numbers. The
serial number will contain text if that matters.

Thanks in advance,

 

[Biff]

Hi!

Use Data Validation.

Select the range in question. Assume that range is A1:A10.

Goto Data>Validation
From the Allow list select Custom
In the Formula box enter:

=COUNTIF(A$1:A$10,A1)=1

OK out.

Biff

 

[Jason Morin]

Using Validation is one way. See Debra D.'s site for
instructions:

http://www.contextures.com/xlDataVal07.html#Unique

HTH
Jason
Atlanta, GA