I have problems to set rating for a movie using .net webclient. I also tried it with .net webrequest. But i didnt get it to work. Hope anyone can help me.

Private Function getGuestSessionId() As String
          
            dim api As String = "xxx"

            Dim WebClient As New WebClient
            WebClient.Headers.Add("Accept", "application/json")
            Dim _json As String = WebClient.DownloadString("http://api.themoviedb.org/3/authentication/guest_session/new?api_key=" & api)
            WebClient.Dispose()

            Dim arrList As New ArrayList(_json.Split(","c))

            Return Replace(Regex.Replace(arrList(1), "[{:}" & Chr(34) & "]", String.Empty), "guest_session_id", String.Empty)

        End Function

getting the guest_session_id works perfect.

Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
            Try
                Dim api As String = "xxx"

                Dim client As New Net.WebClient
                client.Headers.Add("Content-Type", "application/json")
                client.Headers.Add("Accept", "application/json")
                Dim responsebytes = client.UploadData("http://themoviedb.apiary.io/3/movie/119680/rating?api_key=" & api & "&guest_session_id=" & getGuestSessionId(), _
                                    "POST", System.Text.Encoding.UTF8.GetBytes("{" & vbLf & "    ""value"": 7.5" & vbLf & "}"))

            Catch webex As WebException
                MsgBox(webex.Message)
            Catch ex As Exception
                MsgBox(ex.Message)
            End Try

        End Sub