title: .position() doesn't point to the container
body: <p>I have code like this:</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;div id="item-menu"&gt;
    &lt;ul style="padding-top: 10px; padding-left: 20px;"&gt;
      &lt;li id="item-1"&gt;1&lt;/li&gt;
      &lt;li id="item-2"&gt;2&lt;/li&gt;
      &lt;li id="item-3"&gt;3&lt;/li&gt;
    &lt;/ul&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I want to get each item position relative to the container. In this example I will get each <code>&lt;li&gt;</code> position relative to the <code>&lt;ul&gt;</code>, right?</p>
  
  <p>What should I do to get position of item-1 --> top: 10, left: 20?</p>