Hi guys,

I have a spreadsheet which needs to be used by multiple users, unfortuantely there are too many features on the sheet that don't work in a shared spreadsheet.

I would therefore like to add some kind of splashscreen/message box to tell a user in red writing after 20 minutes "*WARNING& You have been in this spreadsheet for longer than 20 minutes, would you like to exit as other users may want to use this workbook?". If yes is selected the spreadsheet prompts for closing (obviously asking if you would like to save if any changes have been made).

Any help would be appreciated.