DisplayObjects and their Children

programming flash
1

as mentioned in many others threads we have to remove all objects we created manually.
if the DisplayObject has eventlisteners you have to remove them manually, too.

for example:

var circle:Sprite = new Sprite();
circle.addEventListener(Event.ENTER_FRAME, doSomething);
circle.addEventListener(Event.REMOVED_FROM_STAGE, doCleanup);

addChild(circle);

stage.addEventListener(MouseEvent.CLICK, doAction);


function doSomething(event:Event):void {
     trace('enterFrame event running');
}

function doAction(event:MouseEvent):void {
    trace('removing DisplayObject');
    removeChild(circle);
    circle = null;
}

function doCleanup(event:Event):void {
    trace('removing eventlisteners');
    circle.removeEventListener(Event.ENTER_FRAME, doSomething);
}

so i am still a bit confused about removing objects from the stage.
what happens to a child object, if its parent has been removed from the stage?

var circle1:Sprite = new Sprite();
var circle2:Sprite = new Sprite();

circle1.addEventListener(Event.ENTER_FRAME, doSomething);
circle1.addEventListener(Event.REMOVED_FROM_STAGE, doCleanup);
circle2.addEventListener(Event.REMOVED_FROM_STAGE, stillOnStage);

addChild(circle1);
circle1.addChild(circle2);

stage.addEventListener(MouseEvent.CLICK, doAction);

function doAction(event:MouseEvent):void {
    trace('removing DisplayObject');
    removeChild(circle1);
    circle1 = null;
}

function doSomething(event:Event):void {
     trace('enterFrame event running');
}

function stillOnStage(event:Event):void {
     trace('seems i was removed?');
}

function doCleanup(event:Event):void {
    trace('removing eventListener');
    circle1.removeEventListener(Event.ENTER_FRAME, doSomething);
}

so does circle2 still remain on the stage? is it still in the memory? will it get garbage collected? the listener tells me, that it was removed.

regards
michael

Edit:
similar article

Edit:

guess the listeners for the removement should also be removed?

function doCleanup(event:Event):void {
    trace('removing eventListener');
    circle1.removeEventListener(Event.ENTER_FRAME, doSomething);
    circle1.removeEventListener(Event.REMOVED_FROM_STAGE, doCleanup);
    circle2.removeEventListener(Event.REMOVED_FROM_STAGE, doCleanup);
}