Need a warning when a duplicate appears in a column

E

ElFrodo

Hello good people!

Anyone who can help me with following problem:

I need warning to pop up when the user of a sheet is trying to put/write the
same letter, number or word in two different cells in a column.

I must mention that the cells in use are already validated, using a list
validation.

Anyone? :)

Best regards
ELFrodo
 
G

Gord Dibben

You could use Conditional Formatting to color both cells when a duplicate is
entered.

Select A1:A50 and Format>Cells>CF>Formula is:

=COUNTIF($A$1:$A$50,A1)>1

Format to a nice bright red.

To have a warning "pop up" would require VBA code or Data Validation which you
have used already.

If you did use DV you would change the formula to =COUNTIF($A$1:$A$50,A1)=1


Gord Dibben MS Excel MVP
 
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