public static function update_query_string($vars = array(), $uri = null, $secure = null)
	{
		// unify the input data
		if ( ! is_array($vars))
		{
			$vars = array($vars => $uri);
			$uri = null;
		}

		// if we have a custom URI, use that
		if ($uri === null)
		{
			// use the current URI if not is passed
			$uri = static::current();

			// merge them with the existing query string data
			$vars = array_merge(\Input::get(), $vars);
		}

		// return the updated uri
		return static::create($uri, array(), $vars, $secure);
	}