I'd like to have a pop-up message that says "Did you remember to mark-up your
quote?", and if they have they click "Yes" and can move on, and if not "No"
forces them to stay on that tab.

There are 8 total tabs, and I simply need it when the go from the tab labled
"Pricing" to any of the other 7 tabs..

Any idea how I might accomplish this?

I'm not finding any information on how to do this, just information that
says you can enter pop-up messages.

Any help would be greatly appreciated!