Flash Photogallery

I was following and learning a great deal from the Flash/XML Gallery by Kirupa - I have it working at for the most part the coding makes sense.

I have one little issue though. I’m trying to fade out the images.
In the code,

picture._alpha = 0; 

sets the image to 0, but i figured if i wanted to fade it out, i would need something like this:

if (picture._alpha>0) { 
picture._alpha -= 10; 

this doesn’t work. I’ve put it multiple places in the code, including in place of

picture._alpha = 0; 

but I can’t get it to fade. Any ideas?

Thanks for your help and the resources!