Helper to show close button

                private void _showCloseableModal(UIViewController controller) {
			var nav = new UINavigationController(controller);
			nav.NavigationBar.TintColor = UIColor.Black;
			controller.NavigationItem.RightBarButtonItem = new UIBarButtonItem("Close", UIBarButtonItemStyle.Done, (object sender, EventArgs args)=>{
				this.DismissModalViewControllerAnimated(true);	
			});
			this.PresentModalViewController(nav , true);
		}