 				this._thumbButton.y = this.thumbButtonY; 
 				this._thumbButton.x = this.thumbButtonX;
 			}
-        
-		
-		}
-		
+		}
+
+		override public function validateSize():void
+		{
+			super.validateSize();
+			positionThumb(_value);
+		}
+
 		public function get value():Number{
 			return _value;
 		}

		public function set value(v:Number):void{
			_value = v;
			if(!thumbButton) return;
			if(_direction == Direction.HORIZONTAL)
			{
				_thumbButton.x = v*(this.width-_thumbButton.width)/(_maximum-_minimum) ;

				_thumbButton.y = v*(this.height-_thumbButton.height)/(_maximum-_minimum) ;
				thumbButtonY = _thumbButton.y;
			}
		}
		
		public function set thumbButtonHeight(value:Number):void
