Changes

The viewControllerAtIndex method begins by checking to see if the page being requested is outside the bounds of available pages by checking if the index reference is zero (the user cannot page back beyond the first page) or greater than the number of items in the pageContent array. In the event that the index value is valid, a new instance of the ContentViewController class is created and the dataObject property set to the contents of the corresponding item in the pageContent array of HTML strings.

Since the view controller is stored in the storyboard file, the following code is used to get a reference to the storyboard and to create a new ContentViewController instance: