A switch section includes a common terminal connected to a terminal at one end of each of a pair of motors, a first terminal connected to a terminal at the other end of one of the motors and a second terminal connected to a terminal at the other end of the other of the motors, and three-contact switches each including one common contact and two switching contacts. In the switch section two switches corresponding to one direction selected from the up and down directions form a switch group, at least one switch corresponding to the other direction selected from the up and down directions is provided, two switches corresponding to one direction selected from the left and right directions form a switch group, and at least one switch corresponding to the other direction selected from the left and right directions is provided.