Test Menu

side = "back" --Replace back with the side your monitor is on
open = "text" -- Replace text with what you want the monitor to say when it your shop is open
close = "text" -- Replace text with what you want the monitor to say when it your shop is closed
mon = peripheral.wrap(side)

term.clear()
term.setCursorPos(1,1)

function yN()
local n=1
while true do
local x, y=term.getCursorPos()
term.clearLine()
if n==1 then write(">Open<   Close") else write (" Open   >Close<") end
term.setCursorPos(x, y)
a, b=os.pullEvent()
while a~="key" do a, b=os.pullEvent() end
if b==203 and n==2 then n=1 end
if b==205 and n==1 then n=2 end
if b==28 then print("") break end
end
if n==1 then
mon.clear()
mon.setCursorPos(1,1)
mon.write(open)
term.clear()
term.setCursorPos(1,1)
yN()
end

if n==2 then
mon.setCursorPos(1,1)
mon.write(close)
term.clear()
term.setCursorPos(1,1)
yN()
end

return false
end

yN()