A welding system having a welding gun with a self-contained trigger and trigger locking assembly. Thus, in the image server and the image display system, the rich contents of a movie picture can be automatically and efficiently retrieved and transmitted to a mobile phone with lower reproducing ability. The method also involves forming a water soluble material layer over and between the plurality of singulated dies, above the dicing tape. The communications server 220 queries the time server 225 for the current time and then provides the current time to the SPS receiver 210. The method for updating a memory includes detecting a memory block to be updated among a plurality of memory blocks of a memory; and updating only the detected memory block.