title: Javascript: Get mouse position relative to parent element
body: <p>Is there any way to get mouse position relative to it's parent element?</p>
  
  <p>Let's say I have a structure:</p>
  
  <pre><code>&lt;div id="parent"&gt;
      &lt;span class="dot"&gt;&lt;/span&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>When I bring my mouse over <code>span</code> element I need to get its position relative to its parent element (<code>&lt;div id="parent"&gt;</code>). PageX/ClientX give me position relative to page/client area, so it's not working for me.</p>