variables naming

[Algreco]

Hey Guys,

I am trying to name a variable and turn it in that way to the instence name inside a nested movie clip.... hmm....
var image_arr = new Array("1.jpg", "2.jpg", "3.jpg","4.jpg","5.jpg","6.jpg","7.jpg");
var top_image_num = image_arr.length;
var i = 1;
var top_image_holder_num = top_image_num - i;
trace (top_image_holder_num);// no problem here
var Num = "holder"+top_image_holder_num;
trace (Num);//no problem here either! it gives "holder6"

NOW... this works:
this.ImageNew.holder6.swapDepths (3);
But this doesn't!:
this.ImageNew.Num.swapDepths (3);

Pls HeLp  

[Mattias Robo]

Say eval(Num).