Swf problem

Hello,
I have a main swf with buttons on it which load different swfs into a mc.
My problem is when a swf loads above the main swf how do I take the main swf out of play, so people cant use the links on it until they have closed the swf they have opened?
I’ve tried explaining this the best I can, but it’s even confusing me, so let me know if you want to help but don’t understand.
Thanks