Get the seatmap Object
var seatmapObj = ew.ui.getSeatmapController(currentSeatmapNode);
Acticate the seat (seatNode1)
youClickHandler => seatmapObj.activateSeat(seatNode1, true);
Deacticate the seat (seatNode2)
youClickHandler => seatmapObj.activateSeat(seatNode2, false);
Deactivate all selected seats from current seatmap
seatmapObj.deactivateAllSeats();