Your first works, so does your second. You just need to deselect "ignore
blank" in the setup dialogue box


--
Regards,

Peo Sjoblom



"John S. Labarge" <John S. wrote in
message ...
Team,
Try this:
In cell A1, add following "custom" validation:
=not(isblank(b1))

As I see it, this should restrict leaving cell A1 unless cell B1 already
has
a value.

I've also tried =b1<"" and some others. Should be simple but I can't get
it to work. Validation will not fire. For each equation I've tried, I've
cut and pasted the same equation into a field and it works fine.

Thanks.