Say i have in cell A1 a date, 2/4/13, and I want to put a formula in another cell to have the word 'Expired' fill in when the actual date is past 2/4/13?
What if I want to format a cell with a fill color (say light red, dark red font) only when it is completely blank but as soon as anything is input in the cell (space included) it reverts to standard sheet format?
In the future, you should start a new thread instead of tacking on to someone else's. It's easy for an already answered thread to get overlooked, and you won't get your answer. =(
To address the question however, your CF formula would be:
=ISBLANK(A2)
This will evaluate to False even if the user puts a space, or contains a formula.