title: Getting extension of the file in FileUpload Control
body: <p>At the moment i get file extension of the file like :</p>
  
  <pre><code>string fileExt = System.IO.Path.GetExtension(filUpload.FileName);
  </code></pre>
  
  <p>But if the user change the file extension of the file ( for example user could rename "test.txt" to "test.jpg" ), I can't get the real extension . What's the solution ?</p>