         self.animator!.presentationBeforeHandler = {(containerView: UIView) in
             let containerViewHeight = modalVC!.containerView!.frame.size.height
             modalVC!.containerView!.frame.origin.y = -containerViewHeight
-            for subview in modalVC!.containerView!.subviews as [UIView] {
+            for subview in modalVC!.containerView!.subviews as! [UIView] {
                 subview.alpha = 0.5
             }
             

        self.animator!.presentationAnimationHandler = {(containerView: UIView, percentComplete: CGFloat) in
            let containerViewHeight = modalVC!.containerView!.frame.size.height
            modalVC!.containerView!.frame.origin.y = -containerViewHeight + containerViewHeight * percentComplete
            for subview in modalVC!.containerView!.subviews as [UIView] {
                subview.alpha = 0.5 + 0.5 * percentComplete
            }
            

        self.animator!.dismissalAnimationHandler = {(containerView: UIView, percentComplete: CGFloat) in
            let containerViewHeight = modalVC!.containerView!.frame.size.height
            modalVC!.containerView!.frame.origin.y = -containerViewHeight
            for subview in modalVC!.containerView!.subviews as! [UIView] {
                subview.alpha = 0.5
            }
            
