instanceOf problem

My .fla:
www.mentalfabrications.com/main2.fla

So I was using this great menu tutorial www.mentalfabrications.com/threecollapsingmenus.fla which uses the following code to create an array for the menu:

FindMenus = function(){
    for (value in this){
        if (this[value] instanceof MovieClip){
            menus.push(this[value]);
        }
    }
    menus.sort(SortByVertical); // order so the highest is first
}

So it takes all the movie clips in the main menu movie clip and adds them to the array. Everything works fine, however my question is this. I would like to create an animation in my menu to make it look a little snazzier (I had one, but it then added that clip to the array and messed up the size. It thought that since it was a movie clip and thus added to the array, it was part of the menu.)

So I was wondering if there was some other way to signify to add the proper movie clips to the array other than just designating to add ALL movie clips? Like maybe create a new object class and add them all to that? Except the animation movie clips. And then instead of instanceof movieClip some other code that adds the new object class?

Or perhaps there’s some other way?

Hope this makes sense. If you’re confused let me know and I’ll try to explain it more clearly.

Any help would be greatly appreciated as always!

Thanks,
iLan