title: Reverse Find in a string
body: <p>I need to be able to find the last occurrence of a character within an element.</p>
  
  <p>For example:</p>
  
  <pre><code>&lt;mediaurl&gt;http://www.blah.com/path/to/file/media.jpg&lt;/mediaurl&gt;
  </code></pre>
  
  <p>If I try to locate it through using <code>substring-before(mediaurl, '.')</code> and <code>substring-after(mediaurl, '.')</code> then it will, of course, match on the first dot.  </p>
  
  <p>How would I get the file extension?  Essentially, I need to get the file name and the extension from a path like this, but I am quite stumped as to how to do it using XSLT.</p>