Controlling a Movie Clip on the Main Timeline from a loaded SWF?

Question

Is it possible to control a MovieClip on the main timelne from another loaded clip?
I see posts that control loaded clips, but most are all from the loader in the main timeline.  I have a moviclip on the main timeline that I want to make visible or invisible depending on what keyframe is playing in another loaded swf.
If I try to call the movieClip from the loaded SWF I get "error #1119.  Access of possibly undefined property...." because it doesn't exist in the loaded SWF, just the main timeline. 
The old AS2 way just used "_root".  Since "_root" doesn't exist any more, how do you control items on the main TimeLine from a loaded SWF?

Answer 1

I am not clear what you mean because you are saying you are trying to target a movieclip that does not exist where you are trying to target it.
Try using a trace to see what you are targeting when you you target the MovieClip(parent.parent)....
trace(MovieClip(parent.parent));
The other approach I mentioned earlier is the more OOP-correct approach if you would rather try that way.  Here's a rough outline of it...
AS3 - Dispatch Event
http://forums.adobe.com/thread/470135?tstart=120
Example:
Add something to trigger the event in the child (your loaded swf):
dispatchEvent(new Event("eventTriggered")); (
if dispatchEvent problem, see: http://www.kirupa.com/forum/showthread.php?p=1899603#post1899603)
In your loading/parent swf, listen for the complete event on the Loader.contentLoaderInfo.  In the complete event handler, add a listener for the event on the loaded swf.
// event handler triggered when external swf is loaded
function loaderCompleteHandler(event:Event) {
    MovieClip(event.currentTarget.content).addEventListener("eventTriggered", eventHandler);
function eventHandler(event:Event):void {
    trace("event dispatched in loaded swf");
   // this is where your main file can set the visible property of your movieclip