private void AddStockButton_Click(object sender, RoutedEventArgs e)
        {
            StockWindow window = new StockWindow();

            window.Closed += window_Closed;
            window.Show();
        }
        private void UpdateStockButton_Click(object sender, RoutedEventArgs e)
        {
            if (StockAssignmentDatagrid.SelectedItems.Count != 1)
            {
                MessageBox.Show("Please select 1 Entry to edit.", "Info");
                return;
            }
            StockAssignmentView AssignmentEntry = (StockAssignmentView)StockAssignmentDatagrid.SelectedItem;
            StockWindow         window          = new StockWindow(AssignmentEntry);

            window.Closed += window_Closed;
            window.Show();
        }