function yN()
local n=1
while true do
	local x, y=term.getCursorPos()
	term.clearLine()
	if n==1 then
  term.clear()
  term.setCursorPos(1,1)
		print ("[ Start ]")
		print ("  Stop   ")
	else
  term.clear()
  term.setCursorPos(1,1)
		print ("  Start  ")
		print ("[ Stop  ]")
	end
	term.setCursorPos(x, y)
	a, b=os.pullEvent()
	while a~="key" do a, b=os.pullEvent() end
		if b==200 and n==2 then
			n=1
		end
		if b==208 and n==1 then
			n=2
		end
		if b==28 then
			if n==1 then
                                print("Start")
                        else
                                print("Stop")
                        end
			break
		end
end
if n==1 then return true end
if n==2 then return false end
return false
end

yN()