public function setConfig($config_location = NULL)
	{

		static $CAPTCHA_CONFIG = array();
		$path = ( NULL === $config_location )
			? __DIR__ . DIRECTORY_SEPARATOR . 'captcha_config.php'
			: realpath($config_location);

		if ( false === $path ) {
			throw new CaptchaException(
				sprintf("Config File not found in: %s ", $config_location)
			);
		}

		if ( $path ) {

			include_once $path;

			foreach (get_class_vars(get_class($this)) as $key => $value) {

				$config = preg_replace('/^[\_A-Z]/', '\\1', $key);

				if ( array_key_exists($config, $CAPTCHA_CONFIG) ) {
					$this->$key = $CAPTCHA_CONFIG[$config];
				}
			}
		}
	}