Macro to display message every n minutes!

I have a spreadsheet and a macro that creates a new sheet and enters some data into the sheet. The user gets to make some changes to the created sheet and then prints it out. I was wandering if there was any way to have a message coming up every 10 minutes remindnig the user about the new sheet untill it was printed out and then the warnings would stop. Could anyone sugest a good way to do that?
Thank you in advance!