Pop up message in ACCESS Macro

Hello -

I have append queries that I run on a monthly basis.  I am charging a co-work to run these.  I have a form with a button (macro) that will run the append queries.  However, I want to add a pop up massage when the macro button is selected that will say something like "You are about to append your data - are you sure you want to proceed".  If possible, a yes or no button afterwards.

Is this possible???  If so - can someone provide detailed steps to do this?  I've never done this before.

Thanks