title: fatal error: unexpectedly found nil while unwrapping an Optional value swift error
body: <p>I am writing a simple program that shows and takes away images and I keep getting the error</p>
  
  <pre><code>fatal error: unexpectedly found nil while unwrapping an Optional value
  </code></pre>
  
  <p>Here is my code:</p>
  
  <pre><code>@IBAction func BeginButton(sender: AnyObject) {
      self.Retry.hidden = false
      self.Begin.hidden = true
      self.Logo.hidden = true
      self.GameOver.hidden = false
      self.ScoreBoard.hidden = false
  }
  
  @IBAction func RetryButton(sender: AnyObject) {
      self.Begin.hidden = false
      self.Retry.hidden = true
      self.Logo.hidden = false
      self.GameOver.hidden = true
      self.ScoreBoard.hidden = true
  }
  </code></pre>
  
  <p>Please help me!</p>