Controling objects in a loaded swf at any given time

Question

I want to communicate with an object within a loaded swf. I know I can use this event listener and function to do so right when the swf has completed loading:
imageLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, loadSections)
    function loadSections(event:Event):void
            event.target.content.mc.y+=2
But I want to be able to manipulate a given object from the loaded swf at any time not just when the loading is complete. So basically as long as the swf is loaded, is there a way to manipulate objects and call functions within that swf?
Both the external and host swf are AS3.
Thanks

Answer 1

I'll just try to add to what Ned already told you.
IF (and only if) I understood what you're trying to do, all you want is press a button to load a new SWF and then click the loaded swf to unload it, right?
If this is what you want, I think you have to understand that a loader IS a displayObject and it CAN be added to the displayList. It took me a lot of time to understand this so maybe this is where you're having trouble to "think" your application (and I guess it is because you're using holder.addChild(imageLoader);, which is not wrong).
Since a loader is a displayObject that can be added to the displayList, you don't really need a another displayObject do hold it, like a holder.
You can simple use addChild(imageLoader);
Doing so, you will have a "loader" on stage working just like anyother displayObject. You can add listeners to it, you can remove it from stage, change its location and all.
So, as Ned said, when you add a loader to the stage, if you want to remove it, go ahead an remove it!
removeChild(imageLoader);
//or, in your case:
holder.removeChild(imageLoader);
The only thing here (as far as my knowledge goes) is that the loaded content still exists EVEN if it doesn't exist on the displayList anymore. That's why you MUST unload it TOO.
imageLoader.unload();
Doing so you'll send the loader content for GarbageCollection and this will be deleted when more memory is needed.
Another best practice I've noticed is that you should avoid from "creating" a loader from withing a function.
Well, just to give you an idea of what you can do:
import flash.events.MouseEvent;
var req:URLRequest = new URLRequest("external.swf");
var loader:Loader = new Loader();
//A button we have on the timeLine.
myBtn.addEventListener(MouseEvent.CLICK, onClick);
function imageLoaded (e:Event):void {
     addChild(loader);
     loader.addEventListener(MouseEvent.CLICK, unloadAndRemove);
     trace (loader is DisplayObject);
function unloadAndRemove (e:MouseEvent):void {
     e.target.unload();
     removeChild(loader);
function onClick(e:MouseEvent):void {
     loader.contentLoaderInfo.addEventListener(Event.COMPLETE, imageLoaded);
     loader.load(req);
I hope it helps.