addChild

(okvir is a movieClip already present on stage)

if I trace them both I get this:

addChild(thumbSprite);
trace(thumbSprite.parent);
[object MainTimeline]

okvir.addChild(thumbSprite);
trace(thumbSprite.parent);
[object okvir_2]

how can i ask this:

if(thumbSprite.parent != okvir){
okvir.addChild(thumbSprite);
}

and this?

if(thumbSprite.parent != stage){
addChild(thumbSprite);
}