public SelectLists(IEnumerable <string> managersList, IEnumerable <string> dateOfSalesList, IEnumerable <string> productsList) { Managers = managersList.ToList(); Products = productsList.ToList(); DateOfSales = dateOfSalesList.ToList(); DateOfSales.Sort(); Managers.Sort(); Products.Sort(); DateOfSales.Insert(0, "All"); Managers.Insert(0, "All"); Products.Insert(0, "All"); }