You can't get an error message since it is not an error in your data
validation,
you could use a cell next to the validation and use a formula there and have
that formula return a message, something like

=IF(AND(C1="Y",B1=""),"YOU NEED TO ENTER A DATE IN CELL B1","")

where C1 is the validation and B1 the date


Regards,

Peo Sjoblom

"Chet Hurd" wrote:

I have setup data validation on a cell to force the user to choose from a
drop down list of words.

How can I make the data validation function put up an error message if the
user picks one of the choices on the list and there happens to be no date
entered in another totally different cell under another column (this other
cell I'm referring to does not have any data validation setup for it)?

- Chet