private void loadProducts()
{
List <Category> categories = DbProduct.GetCategories();
categories.Add(new Category(-1, Application.Current.Resources["cNone"] as String));
PFCat.ItemsSource = categories;
PFCat.DisplayMemberPath = "Title";
Data.Products = DbProduct.GetProducts();
dgProducts.ItemsSource = Data.Products;
bAddProduct.IsEnabled = true;
}