<%= link_to_function "Add new Item" do |page|
    claim_form.fields_for :items, Item.new, :child_index => 'NEW_RECORD'  do |f|
    html = render(:partial => "claims/item_list",
                  :locals => { :form => f })
    page << "$$('tr.item').insert({ bottom: '#{escape_javascript(html)}'.replace(/NEW_RECORD/g, new Date().getTime()) });"
  end
  end%>

# I have a: <tr class="item"></tr>

# Got an error "RJS Error: Type Error: $$('tr.item').insert() is not a function"