I'd use a formula in G3:

=IF(COUNTA(E3:F3)<2,"0k","Only one value!")

or maybe something like:

=IF(COUNTA(E3:F3)=0,"Please enter a value in E or F (not both)",
IF(COUNTA(E3:F3)=1,"0k","Only one value!"))



Gillian wrote:

I have a file with several fields to be entered. Two of the columns are date
fields (say columns E and F). What I want to happen is that if data is
entered in row 3 of column E then it is not possible to enter data in row 3
of column F, and vice versa.
I presume this would be some kind of conditional formatting, but I can't
work out how to do this. I also need to do this in Excel 2000.

--

Dave Peterson