Preloader A.Script Help?

I have made a flash site which loads external SWF’s into a MC when u click on each button. I aint that good with AS. But i Have a preloader within my main SWF which load’s the main.swf, then goes on to play intro etc. Is it possible to adapt each button to use the orignal preloader i have already used at the begining of my main.swf to preload my external SWF’s when you click on each button within my main.swf?
Alright On my main swf page i have my buttons with this current script on each button. If anyone is willing to help me out here & adapt this code for a mc preloader it would mean ALOT?

on (rollOver) {
slider.yMove = home_1._y;

on (release) {

if (_root.currMovie == undefined) {

_root.currMovie = “Homepage”;
} else if (_root.currMovie != “Homepage”) {
if (container._currentframe >= container.midframe) {

_root.currMovie = “Homepage”;;