private void ValidateAppBarButton_Click(object sender, RoutedEventArgs e)
 {
     HTTPRequest connect = new HTTPRequest();
     connect.RequestFinished += new HTTPRequest.RequestFinishedEventHandler(this.doChangePassword);
     connect.HttpPutRequest("https://musicsheetwriter.tk/api/users/" + my_user.PersonalData.Id + "/password", "{ \"current_password\":\"" + this.CurrentPasswordTextBlock.Text + "\",\n\"new_password\":\"" + this.NewPasswordTextBlock.Text + "\" }");
 }