I have a cell to check if it is zero balance, if not, there is a pop-up
message show up to warm people. I tried to use Validation function, but it
only work when you input the data in the cell, but the cell I want it take
effect is fomulated. I can use Conditional Format function, but I want to be
more active to have pop-up message appear when it is invalid. Can anyone
expert help?

Thanks a GREAT!!

Hank