Reading child objects in flash content

Question

I have a vector graphic that originated in Illustrator, which
I then imported into Flash CS3. I converted the graphic elements to
symbols, linking them to AS3 classes, and exported the swf to load
into Flex 3.
I can capture a mouseover event for the individual elements
in the graphic, reading the event.target value just fine, loaded
via the swfLoader or via the Image tag, and feeding the object to
the functions I want to operate on the individual elements.
Now I want to programmatically (and randomly) select the
individual graphic symbols, but can't seem to read them.
In this sample code, which is not working, "background" holds
Flash swf, whether it is a swfLoader, Image, or other Display
Object. The underlying symbols are typed as movie clips, but
casting the selected children as different types doesn't seem to
help.
public function applyRandom():void
var index:int = NumberUtilities.random (0, 100, 1);
var _target:Object;
_target = Object(background.getChildAt(index));
animate(_target);
I've installed Flex Component for Flash CS3 and pulled the
individual components into Flex, but not the whole graphic. Even if
I re-composed the graphic by moving the individual symbols back
into place, in my initial tests, I am running into the same
problem.
Any suggestions would be greatly appreciated.

Answer 1

I have it solved.
loadedMC = MovieClip(background.content);
var _index:int = NumberUtilities.random (0,
loadedMC.numChildren-1, 1);
var _target:Object = Object(loadedMC.getChildAt(_index));
animate(_target);