In a method of forming a patterned thin film, first, an etching stopper film and a film to be patterned are formed in this order on a base layer. A wireless network utilizes a mobile switching center to route communications between wireless stations, a network platform, and a variety of LFE systems. The navigation device is provided with a roller body and includes the ability for detecting the rolling and depression of the roller body and for providing control signals in response thereto. In one embodiment, the time axis depicts time left to right and the call stack position axis depicts call stack position top to bottom.