function ap_lat(ap_code)
  file = assert( io.open("Airports.txt", "r") )
  for line in file:lines() do
    local fields = { line:match("(%w+)|".. ap_code .."|([%w ]+)|([%d-]+)|([%d-]+)|([%d-]+)") }
    if #fields > 0 then
      print(fields[3], fields[4])
    end
  end
  file:close()
end