protected function VerifyCSRFToken($headerName = 'X-CSRFToken')
	{
		// check that a CSRF token is present in the request
		$headers = RequestUtil::GetHeaders();
		
		// make this case-insensitive (IE changes all headers to lower-case)
		$headers = array_change_key_case($headers, CASE_LOWER);
		$headerName = strtolower($headerName);
	
		if (array_key_exists($headerName, $headers))
		{
			if ($this->GetCSRFToken() != $headers[$headerName])
			{
				throw new Exception('Invalid CSRFToken');
			}
		}
		else
		{
			throw new Exception('Missing CSRFToken');
		}
	}