using InWechagMsg member function.

server.go

 //answerWechatPost  distribute PostRequest according to xml body info
 func answerWechatPost(w http.ResponseWriter, r *http.Request) {
 	in, valid := readWechatInput(r)
-	in.instantResponse = make(chan string)
 	reply := "" //nothing
 	w.Header().Set("Content-Type", "text/xml; charset=utf-8")
 
 
 	//read instant response
 	reply = <-in.instantResponse
-	close(in.instantResponse)
+	in.destroy()
 	//uncomment the followin two lines to enable echo test
 	// state, _ := echoCommand(in.header.FromUserName, in)
 	// reply = state.response
 	}
 	valid = true
 	fmt.Printf("decrypt as: %s\n", d)
+	result.init()
 	result.header = ReadCommonHeader(d)
 	switch result.header.MsgType {
 	case "text":