Using Checkboxes and Ajax to Assign Categories

Hi All,

I have an 'admin' controller in which I have a 'show_product' action. In
the view of this action, I have a list of names of the categories w/
checkboxes to the left of each.

What I am trying to do is to allow the administrator to just check off
the categories in this show_product view and have it add the product to
the category.

That part I am not able to figure out is how to display the list of
categories & checkboxes and create observe_form's or observe_field's to
send the product_id and category_id to the action that will do the logic
part.

Here is the code I've got:

# @categories & @product is available to the show_product action as
variables

# _categories.rhtml (partial gets called into the show_product.rhtml
<% if @categories %>
  <% for category in @categories %>
  <div style="clear:both">
    <form id='<%= category.id %>'>
    <%= check_box :category_id, :value => category.id %>
    <%= label :category, :name, category.name %>
    <%= observe_form category.id,
  :frequency => 1.0,
  :update => 'category_notice',
  :url => {
          :controller => 'admin',
          :action => 'update_product_category' },
          :with => "'category=' +
encodeURIComponent($('@category.id').value) + '&product=' +
encodeURIComponent($('@product').value)" %>
    </form>
  </div>
  <% end %>
<br /><br />
<% else %>
  <p>No categories found.</p>
<% end %>