title: Changing button image on different button tag in Xcode
body: <p>I'm creating a custom keyboard for iOS and having a hard time figuring out how to change UIImage of the "shift" key using tags. When the user selects the shift key I'm using:</p>
  
  <pre><code>if( btn.tag == 100 ) {
      btn.setImage(UIImage(named:"shift_en.png"), forState: UIControlState.Normal)
      .......
  }
  </code></pre>
  
  <p>Where "btn" is defined as:</p>
  
  <pre><code>func btnPressed(sender: AnyObject)
      {
          var btn = sender as UIButton
          ........
  </code></pre>
  
  <p>Everything works fine until the user hits a character key and I'd like to "disable" the shift key and change the shift image again. However, since the new "btn" now represents the character key and the tag is changed to the new character tag, how do I change the previous tag UIImage?</p>