Swapping external swf on main stage

Hey guys. This is probably an easy problem for you as3 gurus. I left the Flash world years ago only to come back to it now.

I have a main stage. In the stage are buttons to load external .swfs A, B, C. These buttons work fine using as3 Loader class. A visitor has to manually click on a button after each external swf is played to play the next. I would like A to automatically load B when done… and B to load C.

What I tried to do is to put an action at the end of A telling it to go to root and load B. As we all know, _root is no longer available. I’ve tried many things I’ve read on this forum but has not helped. How would I go about doing this. Hope you guys understand my question. Thanks.