title: Underline button text in Swift
body: <p>I have UIButton. In interface builder I set its title to be 'Attributed'. How can I make its title to be underlined from code in Swift?</p>
  
  <pre><code>@IBOutlet weak var myBtn: UIButton!
  </code></pre>
  
  <p>I created a function called on the touchUpInside event of this button:</p>
  
  <pre><code>var attributedString = NSMutableAttributedString(string:"new text")
      var attrs = [
          NSFontAttributeName : UIFont.systemFontOfSize(19.0),
          NSForegroundColorAttributeName : UIColor.redColor()
      ]
      var gString = NSMutableAttributedString(string:"g", attributes:attrs)
      attributedString.appendAttributedString(gString)
  
      myBtn.titleLabel?.attributedText = attributedString;
  </code></pre>
  
  <p>But still no result. Also I need to know how to access the underline attribute. Text, size and color stay the same.</p>