title: How to change background image on a button , iOS?
body: <p>I created a button on my view controller which has a predefined background image. I created an action and an outlet for this button. I want when the user taps the button to change the background image of this button. How can i do that? 
  I tried to put into the action method of the button something like this:</p>
  
  <pre><code>snapshotCheckbox.image = [UIImage imageNamed:@"snapshot.png"];
  </code></pre>
  
  <p>but i guess this method is for UImageViews. How can i do the same thing for a button?
  Thank you very much for reading my post :D</p>