Loading external image from XML


I am trying to load an external image with the URL being loaded from XML. I know my XML loading is correct, because there are other things which I have loaded. But I have set the URL as a variable, and I am trying to get the image to be externally loaded into _root.profile_mc.picture_mc. The variable is called picture in the profile_mc but I don’t know where to put the AS to load this picture.

Any help would be greatly appreciated.