How to continually iterate through divs with a delay using jQuery?
<p>I have different div columns and would like to perform these steps:</p>

<ol>
<li>iterate through each element every 5 seconds in the first column. A class is added to the element when it is selected and removed when the next element is selected.</li>
<li>when it's finished going through the first column, then move to the second column and iterate through each element in that column just like in step 1.</li>
<li>When the second column is done, continue iteration in the first column and so on....</li>
</ol>

<p>HTML markup:</p>

<pre><code>&lt;div class="first-column"&gt;
  &lt;div class="selected"&gt;...&lt;/div&gt;
  &lt;div&gt;...&lt;/div&gt;
  &lt;div&gt;...&lt;/div&gt;
&lt;/div&gt;
&lt;div class="second-column"&gt;
  &lt;div&gt;...&lt;/div&gt;
  &lt;div&gt;...&lt;/div&gt;
  &lt;div&gt;...&lt;/div&gt;
&lt;/div&gt;
</code></pre>
