internal override string Execute(NameValueCollection commandParameters) { int categoryID; string error = ValidateIntParameter(commandParameters, "categoryId", out categoryID); if (error != string.Empty) { return(error); } List <Category> categoryList; BLClient client = null; // call WCF BLL Method try { client = new BLClient(); categoryList = client.GetCategoryList(categoryID); } catch (Exception exception) { return(ErrorWrapper.SendError(exception.Message)); } finally { if (client != null) { client.Dispose(); } } return(Flatten(categoryList)); }