title: Is the onbeforeunload event not supported on iPhone?
body: <p>So, I've got a handy little bit of functionality in place in a jQuery Mobile app that lets the user know if he/she is navigating away from the page, as this will trigger a log off. In simplified form:</p>
  
  <pre><code>$(window).bind('beforeunload', function() {
    return "Navigating away from this page will log you off. Are you sure you want to continue?";
  });
  
  $(window).unload(function() {
    logoff();
  });
  </code></pre>
  
  <p>This works just great in both Safari and Chrome on my laptop. However, it doesn't appear to work on the iPhone simulator.</p>
  
  <p>Does the mobile browser included in iOS (I know it's Safari, but presumably a different version) simply not support the <code>beforeunload</code> event? Is this true in general for mobile devices (in particular, Android)?</p>