Hi,

Select your column (in this case column A) and then

Data|validation
From the dropdown select Custom and then paste this formula in

=MATCH(A1,$A:$A,0)=ROW(A1)

Mike

"adeel via OfficeKB.com" wrote:

On my work place I maintain record which have Sr. Codes, every time I enter
new record I enter New Sr. Code. please tell me some way that duplicate Codes
not enter. if i try to enter code which I have already enter the error
message come which prompt me for duplicate entry.

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