Shuffle an image with BitmapData – Part 2

import flash.display.BitmapData;
import flash.geom.Rectangle;
import flash.geom.Point;
Array.prototype.shuffle = function() {
	for (x=0; x<24; x++) {
		var from = Math.floor(Math.random()*25);
		var to = this[x];
		this[x] = this[from];
		this[from] = to;
	}
};
big_picture = BitmapData.loadBitmap("scream");
_root.createEmptyMovieClip("big_pic_obj",_root.getNextHighestDepth());
big_pic_obj.attachBitmap(big_picture,_root.getNextHighestDepth());
big_pic_obj._visible = false;
sequence = new Array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24);
sequence.shuffle();
field = new Array();
picture_in = 0;
_root.createEmptyMovieClip("tiles",_root.getNextHighestDepth());
_root.attachMovie("border","border",_root.getNextHighestDepth());
_root.attachMovie("fire","fire",_root.getNextHighestDepth());
border.onEnterFrame = function() {
	this.gotoAndStop(1);
	if (!dragging) {
		this._x = Math.floor(_root._xmouse/100)*100;
		this._y = Math.floor(_root._ymouse/100)*100;
	}
	else {
		dist_x = _root._xmouse-save_x;
		dist_y = _root._ymouse-save_y;
		angle = Math.atan2(dist_y, dist_x)*180/Math.PI;
		if (angle<45 and angle>-45) {
			this.gotoAndStop(3);
			possible_direction = "right";
		}
		if ((angle<-45) and (angle>-135)) {
			this.gotoAndStop(2)
			possible_direction = "up";
		}
		if (angle<-135 or angle>135) {
			this.gotoAndStop(5)
			possible_direction = "left";
		}
		if (angle<135 and angle>45) {
			this.gotoAndStop(4)
			possible_direction = "down";
		}
	}
};
for (x=0; x<25; x++) {
	field[x] = -1;
	picture = tiles.createEmptyMovieClip("small_pic_obj_"+x, tiles.getNextHighestDepth());
	small_picture = new BitmapData(100, 100);
	picture.attachBitmap(small_picture,tiles.getNextHighestDepth());
	small_picture.copyPixels(big_picture,new Rectangle(0+(x%5)*100, 0+Math.floor(x/5)*100, 100, 100),new Point(0, 0));
	picture._alpha = 0;
	picture.id = x;
	picture.onEnterFrame = function() {
		if (this.dir == "right") {
			position = Math.floor(this._x/100)+5*Math.floor(this._y/100);
			if ((position%5 != 4) and (field[position+1] == -1)) {
				this._x += 100;
				field[position] = -1;
				field[position+1] = this.id;
			}
			else {
				this.dir = "";
			}
		}
		if (this.dir == "down") {
			position = Math.floor(this._x/100)+5*Math.floor(this._y/100);
			if ((position+5<25) and (field[position+5] == -1)) {
				this._y += 100;
				field[position] = -1;
				field[position+5] = this.id;
			}
			else {
				this.dir = "";
			}
		}
		if (this.dir == "left") {
			position = Math.floor(this._x/100)+5*Math.floor(this._y/100);
			if ((position%5 != 0) and (position != 1) and (field[position-1] == -1)) {
				this._x -= 100;
				field[position] = -1;
				field[position-1] = this.id;
			}
			else {
				this.dir = "";
			}
		}
		if (this.dir == "up") {
			position = Math.floor(this._x/100)+5*Math.floor(this._y/100);
			if ((position-5>0) and (field[position-5] == -1)) {
				this._y -= 100;
				field[position] = -1;
				field[position-5] = this.id;
			}
			else {
				this.dir = "";
			}
		}
	};
}
_root.onMouseDown = function() {
	position = Math.floor(_root._xmouse/100)+5*Math.floor(_root._ymouse/100);
	if (position == 0) {
		if (field[1] == -1) {
			tiles["small_pic_obj_"+sequence[picture_in]]._alpha = 100;
			tiles["small_pic_obj_"+sequence[picture_in]].dir = "right";
			picture_in++;
		}
	}
	else {
		if (field[position] != -1) {
			dragging = true;
			save_x = border._x+50;
			save_y = border._y+50;
		}
	}
};
_root.onMouseUp = function() {
	position = Math.floor(save_x/100)+5*Math.floor(save_y/100);
	tiles["small_pic_obj_"+field[position]].dir = possible_direction;
	dragging = false;
};