A method and apparatus for operating a multi-user interactive display system including a display having a touch-sensitive display surface. The support structure includes two sections removably coupled together with an improved coupling assembly. Embodiments are presented for method, apparatus, and tangibly stored computer program. The pump body can further define a plunger port disposed between the inlet port and the outlet port. This results in consistent and reliable solder bump formation. An emission unit 20 superposes the pulse laser light LB and the pulse laser light SHG on the same optical axis and focuses, and irradiates a welding point K on welding pieces with, the pulse laser light LB and the pulse laser light SHG.