Dynamically loading images issue//

I’m doing a site where I have a main movie and sub movies that I load using the loadMovie command. In one of the sub movies I want to dynamically load images into a blank movie clip. I can get the images to load if the sub movie is viewed on it’s own but, when the sub movie is loaded into the Main movie the images won’t load. I guess I’m not sure what to replace the “_root” with. Here’s the code (pic_holder is the blank clip):

on (release) {
_root.pic_holder.loadMovie(“test1.jpg”);
}

Since “_root” always references the Main move I tried the following variations with no success:

on (release) {
_parent.pic_holder.loadMovie(“test1.jpg”);
}

and

on (release) {
this.pic_holder.loadMovie(“test1.jpg”);
}

thanks