public static int customerNumber; // customer number that will be used in the CustomerDetails windos
        public CustomerL()
        {
            InitializeComponent();

            GridView gridView = new GridView();

            listViewCustomers.View = gridView;
            gridView.Columns.Add(new GridViewColumn {
                Header = "Customer Ref No ", DisplayMemberBinding = new Binding("Id")
            });
            gridView.Columns.Add(new GridViewColumn {
                Header = "Customer's Name  ", DisplayMemberBinding = new Binding("Name")
            });
            gridView.Columns.Add(new GridViewColumn {
                Header = "Customer's Address ", DisplayMemberBinding = new Binding("Address")
            });

            // iterates through all customers and adds them to the lisView
            foreach (var customer in DataLayerFacade.GelAllCustomersInfo())
            {
                listViewCustomers.Items.Add(customer);
            }
        }