 	 */
 	public class ForceDirectedLayout extends Layout
 	{
-		private var _lookup:Dictionary = new Dictionary();
 		private var _sim:Simulation;
 		private var _step:Number = 1;
 		private var _iter:int = 1;
 		private var _gen:uint = 0;
-		
-		// simlation defaults
+		private var _enforceBounds:Boolean = false;
+		
+		// simulation defaults
 		private var _mass:Number = 1;
 		private var _restLength:Number = 30;
 		private var _tension:Number = 0.1;

		
		/** The physics simulation driving this layout. */
		public function get simulation():Simulation { return _sim; }
		
		// --------------------------------------------------------------------
		

		{
			var p:Particle = d.props.particle;
			if (!p.fixed) {
				var o:Object = _t.$(d);
				o.x = p.x;
				o.y = p.y;
			}
			return true;
		}
