Passing a hidden field to insert_html

I’m trying to pass a hidden field (item_property) to the add_link
helper function but when I do it the process threads start eating up
memory and my computer freezes.

def add_link(name) link_to_function name do |page| page.insert_html :bottom,:partial, :partial => 'item', :object => Item.new(:item_property => "Some text") #adding this parameter creates a problem end end

... <%= f.hidden_field :item_property, :index => nil %> <%= f.text_field :item_text, :index => nil %>

<%= add_link "+Add Field Dinamically" %>
Does anybody know how to define a property of a new object in this
context? I’ve been trying to figure it out for a month, so any help is
very appreciated.
Thanks

Nacho