How to unload this movie from cash?

import mx.transitions.Tween;
import mx.transitions.easing.*;

var myGalleryXML = new XML();
myGalleryXML.ignoreWhite = true;
myGalleryXML.load(“gallery.xml”);

myGalleryXML.onLoad = function() {
gallery_x = myGalleryXML.firstChild.attributes.gallery_x;
gallery_y = myGalleryXML.firstChild.attributes.gallery_y;
gallery_width = myGalleryXML.firstChild.attributes.gallery_width;
gallery_height = myGalleryXML.firstChild.attributes.gallery_height;

myImages = myGalleryXML.firstChild.childNodes;
myImagesTotal = myImages.length;

thumb_height = myGalleryXML.firstChild.attributes.thumb_height;
thumb_width = myGalleryXML.firstChild.attributes.thumb_width;

full_x = myGalleryXML.firstChild.attributes.full_x;
full_y = myGalleryXML.firstChild.attributes.full_y;

callThumbs();
createMask();
scrolling();

};

function callThumbs() {
createEmptyMovieClip(“container_mc”,getNextHighest Depth());
container_mc._x = gallery_x;
container_mc._y = gallery_y;

var clipLoader = new MovieClipLoader();
var preloader = new Object();
clipLoader.addListener(preloader);

for (i=0; i<myImagesTotal; i++) {
thumbURL = myImages.attributes.thumb_url;
myThumb_mc = container_mc.createEmptyMovieClip(i, container_mc.getNextHighestDepth());
myThumb_mc._y = thumb_height*i;
clipLoader.loadClip(“thumbs/”+thumbURL,myThumb_mc);

preloader.onLoadStart = function(target) {
target.createTextField(“my_txt”,target.getNextHigh estDepth(),0,0,100,20);
target.my_txt.selectable = false;
};

preloader.onLoadProgress = function(target, loadedBytes, totalBytes) {
target.my_txt.text = Math.floor((loadedBytes/totalBytes)*100);
};

preloader.onLoadComplete = function(target) {
new Tween(target, “_alpha”, Strong.easeOut, 0, 100, .5, true);
target.my_txt.removeTextField();
target.onRelease = function() {
callFullImage(this._name);
};

target.onRollOver = function() {
this._alpha = 50;
};

target.onRollOut = function() {
this._alpha = 100;
};

};
}
}

function callFullImage(myNumber) {

myURL = myImages[myNumber].attributes.full_url;
myTitle = myImages[myNumber].attributes.title;
createEmptyMovieClip(“fullImage_mc”,getNextHighest Depth());
fullImage_mc._x = full_x;
fullImage_mc._y = full_y;

var fullClipLoader = new MovieClipLoader();
var fullPreloader = new Object();
fullClipLoader.addListener(fullPreloader);

fullPreloader.onLoadStart = function(target) {
target.createTextField(“my_txt”,fullImage_mc.getNe xtHighestDepth(),0,0,200,20);
target.my_txt.selectable = false;
};

fullPreloader.onLoadProgress = function(target, loadedBytes, totalBytes) {
target.my_txt.text = Math.floor((loadedBytes/totalBytes)*100);
};

fullPreloader.onLoadComplete = function(target) {
new Tween(target, “_alpha”, Strong.easeOut, 0, 100, .5, true);
target.my_txt.text = myTitle;
};

fullClipLoader.loadClip(“full_images/”+myURL,fullImage_mc);

}

function createMask() {

createEmptyMovieClip(“mask_mc”,getNextHighestDepth ());

mask_mc._x = gallery_x;
mask_mc._y = gallery_y;

mask_mc.beginFill(0x000000,100);
mask_mc.lineTo(gallery_width,0);
mask_mc.lineTo(gallery_width,gallery_height);
mask_mc.lineTo(0,gallery_height);
mask_mc.lineTo(0,0);

container_mc.setMask(mask_mc);

}

function scrolling() {
onEnterFrame = function() {

container_mc._y += Math.cos(((mask_mc._ymouse)/mask_mc._height)*Math.PI)*15;

if (container_mc._y>mask_mc._y) {
container_mc._y = mask_mc._y;
}

if (container_mc._y<(mask_mc._y-(container_mc._height-mask_mc._height))) {
container_mc._y = mask_mc._y-(container_mc._height-mask_mc._height);
}

};

}