How to load empty movie clip...?

hi all!

easy question here. how to load an empty movie clip with a swf.
i already have the button calling for the swf just fine:

on (release) {

(no errors)
and i already have the empty movie clip on my root timeline.

once i create the “gallery.swf” how do i get it to load? i remember it had to be in the same folder or something like that…it’s been a while.