[Bison]

Are there any more methods to checking proxies than this:

        
if ($HTTP_SERVER_VARS['HTTP_FORWARDED']!="") {
      $proxyip=$HTTP_SERVER_VARS['HTTP_FORWARDED'];
    } elseif ($HTTP_SERVER_VARS['HTTP_X_FORWARDED_FOR']!="") {
      $proxyip=$HTTP_SERVER_VARS['HTTP_X_FORWARDED_FOR'];
    } elseif ($HTTP_SERVER_VARS['HTTP_CLIENT_IP']!="") {
      $proxyip=$HTTP_SERVER_VARS['HTTP_CLIENT_IP'];
    } else {
      $proxyip="";
    }
    $proxyip=xss_clean($proxyip);

All this seems to do is match similarities in the actual IP address ... doesn't do a good job at detecting proxies. I have tested this code with all types of proxies and I aint getting nothing!