Looking for way to test for an unsaved record in Rails 3

I need to do an html delete if the record isn't saved, so in Rails 2, all I had to do was: <% if person_form.object.new_record? %>         <%= link_to_function "Delete", "delete_row()" %> <% else %> ....

object doesn't seem to be there, and rails 3 seems angry about the fields_for that defines person_form in Rails 2. I'm trying to do this in Rails 3 and having no luck.. Please help

Thanks

Bob Smith <bsm2th@gmail.com>

Both ActionView::Helpers::FormBuilder#object() and ActiveRecord::Persistence#new_record?() exist in rails 3. Here is how "Ruby on Rails 3 Tutorial" uses them:

<%= form_for(@user) do |f| %>

  <%= render 'some/partial', :object => f.object %>

Then a local variable named 'object' is available in the partial and it is equal to @user (at least that is the way things appear to work).

class User < ActiveRecordBase

  ...   ...   def some_action     if new_record?        #do something     end   end

and rails 3 seems angry about the fields_for that defines person_form in Rails 2

You should post your code.