Shadow toggled on click

/**
 * Copyright Fumio ( http://wonderfl.net/user/Fumio )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/wf3U
 */

package  {
	import flash.display.Sprite;
	import flash.display.Shape;
	import flash.display.Graphics;
	import flash.filters.DropShadowFilter;
	import flash.events.MouseEvent;
	import flash.events.Event;
	public class Shadow extends Sprite {
		private var circle:Sprite = new Sprite();
		private var shadow:DropShadowFilter = new DropShadowFilter(2, 45, 0x0, 1, 20, 20);
		private var _filters:Array = [];
		public function Shadow() {
			addChild(circle);
			circle.x = stage.stageWidth / 2;
			circle.y = stage.stageHeight / 2;
			addEventListener(MouseEvent.CLICK, toggleShadow);
			draw();
			toggleShadow(null);
		}
		private function draw():void {
			var _graphics:Graphics = circle.graphics;
			_graphics.beginFill(0x00FFFF);
			_graphics.drawCircle(0, 0, 50);
			_graphics.beginFill(0xFFFF00);
			_graphics.drawCircle(25, 20, 30);
		}
		private function toggleShadow(eventObject:MouseEvent):void {
			if (_filters.length) {
				_filters.length = 0;
			} else {
				_filters[0] = shadow;
			}
			circle.filters = _filters;
		}
	}
}