golang telegram send msg

func SendTelegram(msg string) {
    //生成要访问的url
    botid := "1234"
    bottoken := "abcd"
    chatid := "5678"
    url_api := "https://api.telegram.org/"
    url_full := url_api + "bot" + botid + ":" + bottoken + "/sendMessage"
    data := url.Values{"chat_id": {chatid}, "text": {msg}}

    //proxy
    if global.EnableHttpProxy {
        global.HTTPClient = util.SetHttpProxy()
    }
    resp, err := global.HTTPClient.Post(url_full,
        "application/x-www-form-urlencoded",
        strings.NewReader(data.Encode()))
    if err != nil {
        log.Println(err)
    }

    defer resp.Body.Close()

    _, err = ioutil.ReadAll(resp.Body)
    if err != nil {
        log.Println(err)
    }
}