validation column

[benny]

Hi all,
I have a problem to make validation to prevent duplication value in column.
Suppose I have arrays of data in column A (Employee ID) that contains
values, i want to no duplication value when i entering new data. If i
entered the same value as previous row then error message should be alert.

Any body can help what should the formula function applied. Thanks in
advance.

cheers.

 

[Bob Umlas]

Select all of column A. Assuming A1 is active, use Data/Validation, Select
Custom, enter =COUNTIF(A:A,A1)=1 then put in your error message.
Bob Umlas
Excel MVP

 

[benny]

well done, many thanks for your help

best regards