MovieClip still exists without being displayed

Hello everyone, I’m callinf for help because I get a weird problem :

I add a movie clip on a displayobject like this : (mc is a MovieClip with frames on it)


mc = new Mc();
levels.addChild(mc);

So here it is, my mc is displayed on levels object…
For debug reason at each frame in my mc object i use :

trace("mcMoves on "+parent )
//it traces "mcMoves on [object Levels]"

Now i want to remove it (and all the objects displayed on the level object) like this:

while (levels.numChildren) levels.removeChildAt(0);
levels = null;

So everything disappears, but it still trace :
“mcMoves on null”

so my object just disappear from my view, not from the code, how can i erase my object for good ?