array within an array

Hi, hoping someone can help, or at least suggest a better way of
doing the following.

I have two models which have a has_and_belongs_to_many relationship.
for example products and items. On my page view I provide a selection
list (collection_select) of the products, and when the user changes
the selection I fetch the items that are relevant to that product.
However as part of optimising the code I've been using the following
when assigning the products variable

@products =
Product.find(:all, :include=>[:items],:order=>"products.description")

I then bind the product dropdown with @products, and subject to what
selection they make I need to pass the correct items to an item
partial. I know this has to be done by effectively passing
@products[0].items, but how do I figure out where in the array my
original product is, e.g. :products[0] or @products[1]... at the
moment I can only think of looping over the @products array looking
for a matching id and when I've got that pass the items and break out
of the loop. I'm pretty certain there must be a cleaner way rather
than manually coding the loop?

Any ideas or suggestions would be greatly appreciated.

thanks

Pass in the product_id to the partial, without doing eager loading of the items.

@products = Product.find(:all, :order => “description”)

Then do a
@product = Product.find(params[:id])
@product.items

to get the items in the partial.