title: How can I get file extensions with JavaScript?
body: <p>See code: </p>
  
  <pre><code>var file1 = "50.xsl";
  var file2 = "30.doc";
  getFileExtension(file1); //returns xsl
  getFileExtension(file2); //returns doc
  
  function getFileExtension(filename) {
      /*TODO*/
  }
  </code></pre>