Scrolling thumbs._x undefined

1

Hi.

Why the heck can´t things be easy. Look, i thought this was gonna be a piece of cake. I need to scroll some thumbs. Here´s the deal:

I have a mc on stage (_root.thumbs), inside is another mc with the actual thumbs (_root.thumbs.scroller) and a mask so it stays inside _root.thumbs.

Now on 1st frame i have my function thats supposed to slide _root.thumbs.scroller. Plain and simple:


function scrollThumbsL(){
    this.thumbs.scroller._x -= 10;
}

Then i have this button that calls this function on rollOver. Here´s the code:



on(rollOver){
	id = setInterval (scrollThumbsL , 1000);
}
on(rollOut){
	clearInterval(id);
}

So that will not work. If i trace (this.thumbs.scroller._x) i get undefined.

Why? I:-)