Hi,

I need validation on a cell where if any value is entered in one cell the
user MUST enter a value in an adjacent cell. This must be easier than I'm
making it..

e.g

If they enter a number in say A2, a I need to ensure they can't progress
without also entering a number in A3.
Equally, if they enter a number in say A3, a I need to ensure they can't
progress without also entering a number in A2.


The numbers have logical relationship (i.e <=) , but are mutually exclusive,
I can't have one without the other.

Is this a custom formula in the Validation box?