I am trying to build my Xcode project however, I keep getting "Could not find member " build errors in three different instances from the code below. Please help.

Instances:

1. Could not find member 'dataSource'

2&3. Could not find member 'Forward'

import UIKit

class ViewController: UIViewController, UIPageViewControllerDataSource {
    
    var pageViewController: UIViewController!
    var pageTitles: NSArray!
    var pageImages: NSArray!

    override func viewDidLoad() {
        super.viewDidLoad()
    
        self.pageTitles = NSArray(objects: "Welcome", "Hello")
        self.pageImages = NSArray(objects: "page1", "page2")
        
        self.pageViewController = self.storyboard?.instantiateViewControllerWithIdentifier("PageViewController") as! UIPageViewController
        
        self.pageViewController.dataSource = self
        
        var startVC = self.viewControllerAtIndex(0) as ContentViewController
        var viewControllers = NSArray(object: startVC)
        
        self.pageViewController.setViewControllers(viewControllers, direction: .Forward, animated: true, completion: nil)
        
        self.pageViewController.view.frame = CGRectMake(0, 30, self.view.frame.width, self.view.frame.size.height - 60 )
        
        self.addChildViewController(self.pageViewController)
        self.view.addSubview(self.pageViewController.view)
        self.pageViewController.didMoveToParentViewController(self)
        
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    @IBAction func restartAction(sender: AnyObject) {
        
        var startVC = self.viewControllerAtIndex(0) as ContentViewController
        var viewControllers = NSArray(object: startVC)
        
        self.pageViewController.setViewControllers(viewControllers, direction: .Forward, animated: true, completion: nil)
        
    }

    func viewControllerAtIndex(index: Int) -> ContentViewController
        
    {
        
        if ((self.pageTitles.count == 0) || (index >= self.pageTitles.count))
        {
            return ContentViewController()
        }
        
        var vc: ContentViewController = self.storyboard?.instantiateViewControllerWithIdentifier("ContentViewController") as! ContentViewController
        
        vc.imageFile = self.pageImages[index] as! String
        vc.titleText = self.pageTitles[index] as! String
        vc.pageIndex = index
        
        return vc 
        
        
    }
    
    //MARK: - Page View Controller Data Source
    
    func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController? {
        
        var vc = viewController as! ContentViewController
        var index = vc.pageIndex as Int
        
        if (index == 0 || index == NSNotFound)
        {
            return nil
        }
        
        index--
        return self.viewControllerAtIndex(index)
        
    }
    
    func pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController? {
        
        var vc = viewController as! ContentViewController
        var index = vc.pageIndex as Int
        
        if (index == NSNotFound)
        {
            return nil
        }
        
        index++
        if (index == self.pageTitles.count)
        {
            return nil
        }
        
        return self.viewControllerAtIndex(index)
        
    }
    
    func presentationCountForPageViewController(pageViewController: UIPageViewController) -> Int {
        return self.pageTitles.count
    }
    
    func presentationIndexForPageViewController(pageViewController: UIPageViewController) -> Int {
        return 0
    }
    
}