1. admin/edit.rhtml

<% form_tag :action => 'update', :id => @pro<CARET>duct do %>

2. Alt+F7 - Search N1
3. admin_controller.rb

 def edit
    @prod<CARET>uct = Product.find(params[:id])
 end

4. Alt+F7 - Search N2
5. store_controller.rb

def add_to_cart
    product = Product.find(params[:id])  
end

To search attempts return different results.
First search returns usage of local variable "product" described in step 5