Computercraft attempt to index ? (a number value)

os.pullEvent = os.pullEventRaw

rednet.open("left")
local serverId = 14
local done = false
local myId = os.computerID()

while done == false do

  term.clear()
  term.setCursorPos(1,1)
  write("Password:")
  local password = read()
  term.clear()
  term.setCursorPos(1,1)

  if password == "ADMIN" then
    done = true
  else
    rednet.send(serverId.password)
    senderId.message.distance = rednet.receive(5)
    if senderId == serverId then
      if message == "Valid" then
        print("Access Granted")
        redstone.setOutput("top",true)
        sleep(3)
        redstone.setOutput("top",false)
      else
        print("Access Denied")
        sleep(1)
        print("Goodbye")
        redstone.setOutput("back",false)
        sleep(3)
        redstone.setOutput("back",true)
            end
    end
  end
end