title: Fade buttons and labels in objective c for iPhone
body: <p>Hi I want to implement a general fade and reveal algorithm for a mix of UIButtons and UILabels for iPhone. I set the method to receive the object as id.
  But I don't know how to get and set the alpha values for id objects.</p>
  
  <p>I first tried myObject.alpha and then tried <code>[myObject getAlpha]</code> but Xcode says <code>getAlpha</code> method is not found. Anyone knows how to get the alpha value of an id object or recommend another way to do this?</p>