title: Swift - Pushing ViewController in gives a black screen
body: <p>So I have one View Controller that holds a tableView. Whenever a tableview cell is clicked, another view controller is pushed in. This new view controller has its own xib. file and swift file. I have a mapview in the new viewcontroller, but the new view controller is black when pushed in. How do I fix this?
  TableView didSelectRowAtIndexPath method:</p>
  
  <pre><code> func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
      var cell = tableView.cellForRowAtIndexPath(indexPath) as BusinessTableViewCell
      var business = self.results[indexPath.row]
      var mapView = BusinessMapViewController()
      mapView.business = business
      mapView.mapView = MKMapView()
      self.navigationController?.pushViewController(mapView, animated: true)
      println("\(business.name) SELECTED")
  }
  </code></pre>
  
  <p>New View controller:</p>
  
  <pre><code>import UIKit
  import MapKit
  class BusinessMapViewController: UIViewController {
  
  @IBOutlet weak var mapView: MKMapView!
  var business:Business!
  override func viewDidLoad() {
      super.viewDidLoad()
      // Do any additional setup after loading the view.
      let location = CLLocationCoordinate2D(
          latitude: 37.774929,
          longitude: -122.419416
      )
      let span = MKCoordinateSpanMake(0.1, 0.1)
      let region = MKCoordinateRegion(center: location, span: span)
      println(business.latitude)
      mapView.setRegion(region, animated: true)
  }
  
  override func didReceiveMemoryWarning() {
      super.didReceiveMemoryWarning()
      // Dispose of any resources that can be recreated.
  }
  
  
  /*
  // MARK: - Navigation
  
  // In a storyboard-based application, you will often want to do a little preparation before navigation
  override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
      // Get the new view controller using segue.destinationViewController.
      // Pass the selected object to the new view controller.
  }
  */
  </code></pre>
  
  <p>}</p>