Security Card Door

while true do
  if not fs.exists("config.cfg") then
    local f = fs.open("config.cfg","w")
    print ("What is the gate's accreditation level ? ")
    local lvl = read()
    f.write(lvl)
    f.close()
  end

 local _, side = os.pullEvent("disk")
 local f = fs.open("config.cfg","r")
 local lvl = f.readLine()
 f.close()

   if fs.exists("disk/lvl.info") then
     local f2 = fs.open("disk/lvl.info","r")
     local l = f2.readLine()
     f2.close()
     l = tonumber(l)
     lvl = tonumber(lvl)
     print(lvl)
     print(l-lvl)
     if l-lvl >= 0 then
       rs.setOutput("bottom",true)
       disk.eject(side)
       sleep(3)
       rs.setOutput("bottom",false)
     end
   end
end