Hi this is my first time working with formulas from scratch so I need some
assistance.

I just need to create a formula that will provide a message in a different
cell (not in a popup message) if a range of cells (ie: A3:A30) are all
filled, no cells are left blank.

What I'm trying to do is create a self registration for people to sign up
for classes and once all cells are filled with names I want a message to
appear saying "Sorry this Class is filled, Pls contact......")

Thanks!