access token also using config parameter

accessToken.go

 //issue web request to get token from wechat
 func renewAuthtoken() (authToken, error) {
 	//url := "http://vimeo.com/api/v2/brad/info.json"
-	url := "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=wx876e233fde456b7b&secret=4a91aa328569b10a9fb97adeb8b0af58"
+	url := fmt.Sprintf("https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=%s&secret=%s", APIConfig.Appid, APIConfig.AppSecret)
 	var myClient = &http.Client{Timeout: 20 * time.Second}
 	r, err := myClient.Get(url)
 	if err != nil {

main.go

 	nonce, nok := m["nonce"]
 	token := APIConfig.Token
 	if sok && tok && nok {
-
+		//sort token, timestamp, nonce  and join them
 		strs := []string{token, timestamp[0], nonce[0]}
-
 		sort.Strings(strs)
 		s := strings.Join(strs, "")
 
+		//calculate sha1
 		h := sha1.New()
 		h.Write([]byte(s))
-		us := fmt.Sprintf("%x", h.Sum(nil))
-		return signature[0] == us
+		calculated := fmt.Sprintf("%x", h.Sum(nil))
+		return signature[0] == calculated
 	}
 	return false
 }