A computer implemented method and system for displaying categorized information on a user interface is provided, in which the user may choose one or more categories of information. Each of the blocks of memory cells can be independently operated in either a single cell mode or a twin cell mode. Two new authoring languages, interactive voice response and speech recognition are used to enable expert and general practitioner knowledge to be encoded for access by the public. As a result, the output beam has a desired orientation with respect to true level.