title: C# detect page redirect
body: <p>I am trying to determine if a qualification exists on <a href="http://www.accreditedqualifications.org.uk" rel="noreferrer">http://www.accreditedqualifications.org.uk</a>
  in the form:</p>
  
  <p><a href="http://www.accreditedqualifications.org.uk/qualification/50084811.seo.aspx" rel="noreferrer">http://www.accreditedqualifications.org.uk/qualification/50084811.seo.aspx</a></p>
  
  <p>50084811 being a qualification aim entered by the end user.</p>
  
  <p>If they enter an invalid one e.g.</p>
  
  <p><a href="http://www.accreditedqualifications.org.uk/qualification/50084911.seo.aspx" rel="noreferrer">http://www.accreditedqualifications.org.uk/qualification/50084911.seo.aspx</a></p>
  
  <p>They are redirected to an error page (with incorrect http headers as far as I can see). Is there a way to detect the redirect in C#. I would hope to be able to detect the redirect in http headers (thinking it will issue 2) or similar as oppose to having to download the whole page. This could be happening a lot so I would like to minimize traffic.</p>
  
  <p><strong>Edit</strong></p>
  
  <p>Used this to have a look at the headers looks like two are issued for an invalid page:</p>
  
  <p><a href="http://pageheaders.com/display-http-headers.php?url=http%3A%2F%2Fwww.accreditedqualifications.org.uk%2Fqualification%2F50084911.seo.aspx&amp;agent=ie6" rel="noreferrer">http://pageheaders.com/display-http-headers.php?url=http%3A%2F%2Fwww.accreditedqualifications.org.uk%2Fqualification%2F50084911.seo.aspx&amp;agent=ie6</a> </p>