title: jQuery(document).on ('focus')?
body: <p>Whenever the user focuses on clicks on an input, I want to trigger a method. 
  I have the following code:</p>
  
  <pre><code>jQuery(document).on('focus click', function(e){
          console.log("focused on " + $(e.target).attr('id'));
  });
  </code></pre>
  
  <p>But whenever I focus on an element it just gives <code>focused on undefined</code>. What's wrong with this code?</p>