Disabling buttons conundrum

1

I’m building a site at the mo with pop up that can be activated and covers the main page with a new info page. This popup can be activated at anytime and will cover whatever is in the main page. Trouble is, buttons are still active from the main page when popup is displayed and given the site design the only way to stop this problem is disabling the buttons below. What is a good way of doing this? I was hoping flash keeps some sort of array of mc content and the buttons could be identifed this way but somehow i don’t think this is likely!