public CustomerQuoteManageViewModel(BaseViewModel parent, int customerId)
        {
            this.parent = parent;

            // Get the list of the customer's quotes
            quoteList = QuoteModel.getCustomersQuotes(customerId);
            customer  = CustomerModel.getCustomer(customerId);

            // Set the heading text using the customer's name
            headingText = "Quotes issued to " + customer.firstname + " " + customer.surname;

            // Keep a copy of the quoteList so that we can restore the list after filtering
            originalQuoteList = new ObservableCollection <QuoteModel>(quoteList);
        }