Using BitmapData to manage a deck of cards

import flash.display.BitmapData;
import flash.geom.Rectangle;
import flash.geom.Point;
import flash.filters.DropShadowFilter;
var distance:Number = 4;
var angleInDegrees:Number = 45;
var color:Number = 0x000000;
var alpha:Number = .5;
var blurX:Number = 4;
var blurY:Number = 4;
var strength:Number = 1;
var quality:Number = 3;
var inner:Boolean = false;
var knockout:Boolean = false;
var hideObject:Boolean = false;
var my_shadow_filter:DropShadowFilter = new DropShadowFilter(distance, angleInDegrees, color, alpha, blurX, blurY, strength, quality, inner, knockout, hideObject);
big_picture = BitmapData.loadBitmap("cardz");
_root.attachMovie("table","table",_root.getNextHighestDepth());
_root.attachMovie("higher","higher",_root.getNextHighestDepth());
_root.attachMovie("lower","lower",_root.getNextHighestDepth());
_root.createEmptyMovieClip("big_pic_obj",_root.getNextHighestDepth());
big_pic_obj.attachBitmap(big_picture,_root.getNextHighestDepth());
big_pic_obj._visible = false;
pictures = new Array();
sequence = new Array();
Array.prototype.shuffle = function() {
	for (x=0; x<52; x++) {
		var from = Math.floor(Math.random()*52);
		var to = this[x];
		this[x] = this[from];
		this[from] = to;
	}
};
for (x=0; x<52; x++) {
	card = _root.createEmptyMovieClip("small_pic_obj_"+x, _root.getNextHighestDepth());
	sequence[x] = x;
	small_picture = new BitmapData(79, 123);
	card.attachBitmap(small_picture,_root.getNextHighestDepth());
	small_picture.copyPixels(big_picture,new Rectangle(0+(x%13)*79, 0+Math.floor(x/13)*123, 79, 123),new Point(0, 0));
	card._visible = false;
	card.filters = new Array(my_shadow_filter);
	card.onEnterFrame = function() {
		switch (this.action) {
			case "come" :
				this._x += 40;
				if (this._x>210) {
					this._x = 210;
					this.action = "stay";
				}
				break;
			case "move" :
				this._x += 20;
				if (this._x>310) {
					this._x = 310;
					this.action = "dissolve";
				}
				break;
			case "dissolve" :
				this._alpha -= 4;
				if (this._alpha<0) {
					can_draw=true;
					this.removeMovieClip();
				}
				break;
		}
	};
}
sequence.shuffle();
cards_drawn = 0;
can_draw = true;
draw_card();
higher.onRelease = function() {
	if(can_draw){
		can_draw=false;
		draw_card();
	}
};
lower.onRelease = function() {
	if(can_draw){
		can_draw=false;
		draw_card();
	}
};
function draw_card() {
	_root["small_pic_obj_"+sequence[cards_drawn]]._x = 0;
	_root["small_pic_obj_"+sequence[cards_drawn]]._y = 30;
	_root["small_pic_obj_"+sequence[cards_drawn]]._visible = true;
	_root["small_pic_obj_"+sequence[cards_drawn]].action = "come";
	_root["small_pic_obj_"+sequence[cards_drawn-1]].action = "move";
	cards_drawn++;
}