Get last child of div in Javascript function
<p>I am taking a fairly simple piece of code and wrapping into a function, the code builds a slide out menu from the items inside a div.  I'm now trying to get the last child from a div:</p>

<pre><code>experimentOne('#experimentOne');

   function experimentOne(masterContainer) {
   var experimentOneMenuButton = $('masterContainer :last-child');
   ... etc
</code></pre>

<p>However, this returns [] in the log.  When I check the width, instead of the 100px it should be, it's 1420 which I'm guessing is the window width.</p>

<p>If I just get the last child of the ID by coding it in everything is fine, but I want the function to be as reusable as possible.</p>

<p>Thanks.</p>
