Pop-up message box macro after conditional formatting?

Hello everyone,

I have set up a conditional format that highlights any data in a column that is repeated. I.e. highlighting duplicates: =COUNTIF(L:L,L172)>1

I would like to know if it is possible to have a pop-up message box appear once a duplicate/highlight appears that informs the user of this fact.

I have only a little bit of experience with VBA so i can't quite figure this one out....

Any help will be greatly appreciated!

Thanks alot in advance.
Peter

That's perfect. Thank you very much VBA Noob!