Data validation based on another cell

[Z]

Im not quite sure what to put in the title, but heres my problem:

I want prevent people from inputing into a cell if other cells have
been filled in.
A1 has no value
B1 has no value
C1 has X
D1 then cannot have a value because A1:C1 has an X in one of the other
three cells

:: but if you make C1 have no value then D1 would be able to input an X
into that cell, however
then the other cells you would not be able to.

Im assuming you would use data validation, things ive tried is custom
data validation with formulas
such as COUNTA(A1:C1)>2, also tried IFTEXT(A1... i tried a few forumlas
which either did nothing, or didnt allow me to do anything.

Anyone have any idea?
Thanks!
Michael

 

[Arvi Laanemets]

Hi

Select A
Enter validation formula:
=COUNTA($A1:$D1)<2
OK


Arvi Laanemets

 

[Z]

Works like a charm! thanks!

Hi

Select A
Enter validation formula:
=COUNTA($A1:$D1)<2
OK

Arvi Laanemets