count number of elements between "this" and "that" element
<p>I'm trying to know how "far" away a clicked element in the DOM is to a certain other element.</p>

<pre><code>&lt;li&gt;item1&lt;/li&gt;
&lt;li&gt;item2&lt;/li&gt;
&lt;li class="active"&gt;item3&lt;/li&gt;
&lt;li&gt;item4&lt;/li&gt;
&lt;li&gt;item5&lt;/li&gt;
&lt;li&gt;item6&lt;/li&gt;
&lt;li&gt;item7&lt;/li&gt;
</code></pre>

<p>So when a user clicks an element it should return the distance to the active element: So <code>item1: return -2</code>, <code>item4: return 1</code>, <code>item6: return 3</code>, and so on.</p>
