Warp beacon

Side = { "bottom", "top", "back", "left", "right" }
for i = 1,5 do
  if peripheral.getType(Side[i]) == "warpcore" then
    beacon = peripheral.wrap(Side[i])
    print("Enter frequency")
    freq=io.read()
    beacon.set_beacon_frequency(freq)
    print("Stand on the top of warp core and wait :)")
    error()
  end
end
print("Can't find warp core!")