function url_encode(str)
  if (str) then
    str = string.gsub (str, "\n", "\r\n")
    str = string.gsub (str, "([^%w %-%_%.%~])",
        function (c) return string.format ("%%%02X", string.byte(c)) end)
    str = string.gsub (str, " ", "+")
  end
  return str
end

local text = url_encode("Dziękuję")
playSound("http://translate.google.com/translate_tts?tl=pl&q=".. text .."&client=tw-ob")