I want to remind users of a workbook that they need to fill in a last updated
cell if they have made any amendments to the sheet.

Is there a way I can get a message to pop up when they go to save the
document so they have to input the 'Last Updated' date in the relevant column
before they save and exit. And if I'm feeling really evil, can I get it to
not allow them to exit unless they've done it?

ps I'm a total VBA novice!