Code

while  true do
 local event = os.pullEvent("redstone")
 local greenState = rs.testBundledInput("left", colors.green)
 if greenState == true then
  redstone.setOutput("right", true)
  sleep(2)
  redstone.setOutput("right", false)
  redstone.setOutput("back", true)
  sleep(1)
  redstone.setOutput("back", false)
  os.shutdown
 else
  print("Please try again later")
  os.shutdown
 end
end