need code help for loading external swfs

hi
im using this tutorial http://www.kirupa.com/developer/mx2004/transitions.htm to help me understand how to build a site that will load external .swfs . The problem is it offers the code is made to apply on butttons and i really need it to work with my rollover mc buttons. any suggestions at code that will work with my MCs and do the samething?
here is the orginal code:

on (release) {
if (_root.currMovie == undefined) {
_root.currMovie = "main";
container.loadMovie("main.swf");
} else if (_root.currMovie != "main") {
if (container._currentframe >=
container.midframe) {
_root.currMovie = "main"; container.play();
}
}

use

movieClipName.onRollOver = function() {
};

instead of

on (release) {
}

perfect, thanks alot for your help