Disclosed is a server computer and method that provides a first user interface to a first client computer operated by a first user for display by a first web browser. The interlocking device has a sliding block and a rotary disc disposed on a fixed base. Only when it is determined that the video phone function is in the effective condition, the control unit starts communication using the video phone function. An acetal-enriched stream is separated from the acetal-containing stream and then hydrolyzed to form a hydrolysis mixture comprising the alcohol and the aldehydes. A second channel is disposed adjacent to the dielectric channel between the conductive plates.