An apparatus and method for controlling selected functions of a machine is provided. The machine includes a seat having at least one armrest supportably positionable adjacent to the seat. An interface module has a connecting portion connectable to the armrest and adapted to shift a working portion laterally between a retracted position and an extended position relative to the armrest. This permits placing the interface module in either a stored mode or a working mode such that it is available to an operator as needed and conveniently out of the way when not needed.