protected void PopulateModelSelectLists(List <Category> categories, List <Author> authors) { //Categories List CategoriesSelectList = categories .Select(x => new SelectListItem() { Value = x.Id.ToString(), Text = x.Name, Selected = SelectedCategories != null && SelectedCategories.Contains(x.Id) }); //Authors list AuthorsSelectList = authors .Select(x => new SelectListItem() { Text = x.FirstName + " " + x.LastName, Value = x.Id.ToString(), Selected = x.Id == AuthorId }); }