Let's now implement the "Edit Product"
functionality of our site. We'll ultimately want users to see a screen
like below when they visit the /Products/Edit/[ProductID] URL:
Figure 31

Like the "Add New Product" form post example
above, we are going to implement this form edit interaction using two
ProductsController Actions that we'll call "Edit" and
"Update":
Figure 32

"Edit" will display the product form.
"Update" will be used to handle the form's submit action.