title: selector in jquery - get rel attribute
body: <p>I have html code like this:</p>
  
  <pre><code>&lt;li id="vol" rel="1"&gt;
      // something here
  &lt;/li&gt;
  &lt;li id="vol" rel="2"&gt;
      // something here
  &lt;/li&gt;
  &lt;li id="vol" rel="3"&gt;
      // something here
  &lt;/li&gt;
  </code></pre>
  
  <p>I'm try to get rel attribute by this code:</p>
  
  <pre><code>$('#vol').click(function(){
    var rel = $(this).attr('rel');
  });
  </code></pre>
  
  <p>But it's not working. I also change <code>this</code> to <code>#vol</code>, but it didn't work.
  What should i do?</p>