A system for performing the desired transaction when the customer follows a specified procedure comprising a sequence of steps includes an electronic visual display unit for displaying a message and a graphic illustration at the same time, and a plurality of functionally operative physically manipulative function units arranged around the display unit. The physical operations are performed by the customer in a sequence of steps, and some of the function units serve different functions for different steps. The display unit displays stepwise, immediately before each of the steps is performed by the customer, an instruction comprising the combination of a procedure specifying textual message describing the procedure to be followed by the customer and a procedure specifying graphic illustration pictorially depicting the physical enactment of the procedure in corresponding relation to the message. In a step in which a function button is to be operated by the customer, the display unit also shows a term indicating the function of the button at a location adjacent and corresponding to the button to be operated and a button frame surrounding the term at least at two sides thereof to indicate the location of the button corresponding to the term.