galería de imágenes horizontal

Buenas, podría alguien ser tan amable de indicarme donde puedo alterear el código y que debería colocar en él para que la galería se torne horizontal en lugar de vertical?
Muchas gracias

Código :

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",getNextHighestDepth());
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[i].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",0,0,0,100,20);
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",getNextHighestDepth());
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",0,0,0,200,20);
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() {
   container_mc.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);
      }
   };
}

En la función "scrolling" (la última). Cambia la "_y" por "_x" y "_height" por "_width"