Player Sensor Alarm

sensor = peripheral.wrap("top")
monitor = peripheral.wrap("right")

local w,h = monitor.getSize()
--rs.setBundledOutput("left",colors.white)
--rs.setOutput("left",false)

function usersCheck(name)

--users
local users = {["USERNAME"] = true,
--If you want more usernames to allow, copy the line below and paste it right under it
["USERNAME"] = true,
["USERNAME"] = true}

length = table.getn(users)

for i=1,length do

  if name ~= users[i] then
  return 1
  end

  if name == users[i] then
  return 2
  end

end
end

while true do
monitor.clear()
i = 2
ww = w/2 - 7
monitor.setCursorPos(ww,1)
monitor.write("Near your base:")
rs.setOutput("left",false)
targets = sensor.getPlayerNames()

for k, v in pairs(targets) do
        name = targets[k]
 tarLeng = table.getn(targets)

   sL = string.len(name)
   ww = w/2 - sL/2 + 1
   monitor.setCursorPos(ww,i)
   monitor.clearLine(i)
   if usersCheck(name) == 2 then
   monitor.setTextColor(8192)
   elseif usersCheck(name) == 1 then
   monitor.setTextColor(colors.red)
   end
   monitor.write(name)
   monitor.setTextColor(1)
   i = i + 1

if usersCheck(name) == 1 then
  --rs.setBundledOutput("left",colors.white)
  print("Warning: Unathorized player in range!")
  rs.setOutput("left",true)
  end

end
sleep(2)
end