     
     override public func continueTrackingWithTouch(touch: UITouch, withEvent event: UIEvent) -> Bool {
         super.continueTrackingWithTouch(touch, withEvent: event)
-
+        
         let lastPoint = touch.locationInView(self)
         
         if lastPoint.x > self.bounds.size.width * 0.5 {

                let thumbX = self.frame.size.width - (self.frame.size.height - 2 - 4 + 4)
                
                self.thumbView.frame = CGRectMake(thumbX, 3, normalKnobWidth, normalKnobWidth)
                self.thumbView.backgroundColor = UIColor.clearColor()
                self.thumbView.layer.borderWidth = 1
                self.thumbView.layer.borderColor = UIColor.whiteColor().CGColor
                
               
                self.onImageView.alpha = 1.0
                self.offImageView.alpha = 0
                self.onLabel.alpha = 1.0
                self.offLabel.alpha = 0
            }, completion: { finished in
                self.isAnimating = false
            })
        }
        else {

        thumbImageView.contentMode = UIViewContentMode.Center
        thumbImageView.autoresizingMask = UIViewAutoresizing.FlexibleWidth
        thumbView.addSubview(thumbImageView)
        
        self.on = false
    }
    
