title: Floating/fixed div in footer
body: <p>I have a wordpress site and I would like to display 1 Google Adsense banner ad (320px x 50px) at the very bottom of the page only to mobile users. When I say at the bottom of the page I should really say the bottom of viewable screen so no matter where on the page the user is it's always visible.</p>
  <p>I have worked out that I need to use media queries and I have found out the size of the main mobile devices that use the site which are either 320px or 360px wide.</p>
  <p>The css I wrote for this and placed in the standard style.css file is;</p>
  <pre><code>@media only screen 
  and (min-device-width : 320px) 
  and (max-device-width : 360px) {
  .mobileadunit {
    width:320px;
    height:50px;
    position:fixed;
    bottom:0px;
    }
  
  }
  </code></pre>
  <p>I then placed the div in the footer.php file on wordpress just before the  tag</p>
  <pre><code>&lt;div class=&quot;mobileadunit&quot;&gt;
  ADSENSE CODE
  &lt;/div&gt;
  </code></pre>
  <p>but despite my best efforts I can't get this to show up. Am I doing something wrong that's glaringly obvious?</p>