title: How to programmatically disable/enable a UIBarButtonItem
body: <p>I currently have a button called <code>continueButton</code> that has been assigned to a UIBarButtonItem button in a Storyboard file. I've declared the button as such:</p>
  
  <pre><code>- (IBAction)continueButton;
  </code></pre>
  
  <p>When the view loads, I want the button to disable itself, so that there can be no user input unless a command is called that re-enables user input for the button. How would I go about doing this? I'm trying to use the function <code>[continueButton setEnabled:YES];</code> to disable/enable the button programmatically, but it doesn't work properly.</p>