title: Adding event listeners without overriding
body: <p>I am setting an <code>eventListener</code> for <code>keyup</code> on a certain input.  Then later in the code, I need to be able to add another event to that listener without overriding the first one (both functions must execute).  Is this possible to accomplish?</p>
  <p>I've tried:</p>
  <pre><code>$input.keyup(function...)
  
  $input.bind('keyup',function(){...});
  
  $input.addEventListener('keyup',function(){...});
  </code></pre>
  <p>and I haven't been able to get any working.</p>