I dont even really know how to word this but I'll give it a go!

What Im looking for, if possible, is to get what you get with a lot of online forms, where they require you to fillout certain fields.

I need my agents to have no choice but to fill out their names and date on their sales sheets. Can I have them not be be able to save a sheet until they have entered this info. And maybe have a dialog/warning box letting them know that they haven't done this when they try to save their spreadsheet.