B4J Question With httpjob Post json to jServer(server handler)

Dim sn As Map=jyAuth.LoadMachineSn
    sn.Put("license",result)           
    Dim jg As JSONGenerator
    jg.Initialize(sn)
    Dim HTTPTask As HttpJob
    HTTPTask.Initialize("HTTPTask", Me)
    HTTPTask.PostString("http://127.0.0.1:8168/registered", jg.ToString)
    HTTPTask.GetRequest.SetContentType("application/json")
    HTTPTask.GetRequest.SetHeader("Accept","application/json")
    wait for (HTTPTask) JobDone(HTTPTask As HttpJob)   
    If HTTPTask.Success Then
        'Json.Initialize(HTTPTask.GetString)
        Log(HTTPTask.GetString)
    End If
HTTPTask.Release