private void AddNewPortfolio(object parameter)
        {
            Portfolio             NewPortfolio = new Portfolio();
            NewPortfolioViewModel NPVM         = new NewPortfolioViewModel();
            NewPortfolioWindow    NPW          = new NewPortfolioWindow();

            NPW.DataContext = NPVM;
            NPW.ShowDialog();
            if (NPW.DialogResult.HasValue && NPW.DialogResult.Value)
            {
                NewPortfolio.PortfolioName = NPW.PortfolioNameTextBox.Text;
            }
            NewPortfolio.BenchmarkInstrument = NPW.BenchmarkInstrumentTextBox.Text;
            NewPortfolio.InceptionDate       = DateTime.Today;
            Portfolios.Add(NewPortfolio);
            RepositoryWriter.WritePortfolio(NewPortfolio.PortfolioName, NewPortfolio.BenchmarkInstrument, NewPortfolio.InceptionDate);
        }