acts_as_list issue

The list i have defined in my acts_as_list will not let me drag the li elements around. I am using FF, but IE6 also fails. Here is what i have defined in my code:

model: listing.rb

class Listing < ActiveRecord::Base   acts_as_list end

view: index.rb

<h1>Listing listings</h1>

<div id="items"> <ul id="item_list">

<% for listing in @listings %>   <li id="item_<%= listing.id %>">     <%=h listing.name %>     <%=h listing.completed_dt %>     <%=h listing.position %>   </li> <% end %> </ul> </div>

<% sortable_element 'item_list', :url => { :action => "sort" } %>

<br />

<%= link_to 'New listing', new_listing_path %>

controller: listings_controller.rb

  ...   def sort   params[:item_list].each_index do |i|     item = Listing.find(params[:item_list][i])       item.position = i       item.save     end     @list = Listing.find(:all, :order => 'position')     render :layout => false, :action => :index   end

I also have all of the javascript includes in the layout and can see them when i view source of the page.

What am i missing? or what is wrong with the code?

Thanks Phil

problem was the invalidauthenticitytoken