The present invention discloses a server automatically detecting a new joining portable device in a wireless local area network and providing the new joining portable device with a new identification number, thereby the portable device can automatically access the wireless LAN and obtain the services from the server. Since the measured distance is longer than a predetermined shortest measured distance, the method can accordingly calculate a proper delay period for ensuring that the reflected light reaches the light-sensing component after the delay period. The apparatus further includes a detector that photoelectrically detects the pattern image and generates a first output signal containing a representation of the image, and position detection system, electrically connected to the detector, that detects a position of the pattern based on the first output signal, and determines a deviation of the position from an ideal position. The conduit passes through the inner float wall, wherein a flow channel is disposed therebetween. The clamping device provides uniform, taut material for accurate, smooth embroidering.