function get_user_ip() {
   $strRemoteIP = $_SERVER['REMOTE_ADDR'];
   if (!$strRemoteIP) {
       $strRemoteIP = urldecode(getenv('HTTP_CLIENTIP'));
   }
   if (getenv('HTTP_X_FORWARDED_FOR')) {
       $strIP = getenv('HTTP_X_FORWARDED_FOR');
   }
   elseif (getenv('HTTP_X_FORWARDED')) {
       $strIP = getenv('HTTP_X_FORWARDED');
   }
   elseif (getenv('HTTP_FORWARDED_FOR')) {
       $strIP = getenv('HTTP_FORWARDED_FOR');
   }
   elseif (getenv('HTTP_FORWARDED')) {
       $strIP = getenv('HTTP_FORWARDED');
   } else {
       $strIP = $_SERVER['REMOTE_ADDR'];
   }
   if ($strRemoteIP != $strIP) {
       $strIP = $strRemoteIP . ', ' . $strIP;
   }
   return $strIP;
}