Updated old fashion form_for samples.

when 'form_for :resource, @resource ...' is found, remove the first argument (there is no need to use the :as option when the name is the same).

railties/guides/source/action_view_overview.textile

@@ -654,7 +654,7 @@ The core method of this helper, form_for, gives you the ability to create a form
 
 <ruby>
 # Note: a @person variable will have been created in the controller (e.g. @person = Person.new)
-<%= form_for :person, @person, :url => { :action => "create" } do |f| %>
+<%= form_for @person, :url => { :action => "create" } do |f| %>
   <%= f.text_field :first_name %>
   <%= f.text_field :last_name %>
   <%= submit_tag 'Create' %>

railties/guides/source/form_helpers.textile

@@ -222,7 +222,7 @@ end
 The corresponding view +app/views/articles/new.html.erb+ using +form_for+ looks like this:
 
 <erb>
-<%= form_for :article, @article, :url => { :action => "create" }, :html => {:class => "nifty_form"} do |f| %>
+<%= form_for @article, :url => { :action => "create" }, :html => {:class => "nifty_form"} do |f| %>
   <%= f.text_field :title %>
   <%= f.text_area :body, :size => "60x12" %>
   <%= submit_tag "Create" %>
@@ -253,7 +253,7 @@ The helper methods called on the form builder are identical to the model object
 You can create a similar binding without actually creating  +&lt;form&gt;+ tags with the +fields_for+ helper. This is useful for editing additional model objects with the same form. For example if you had a Person model with an associated ContactDetail model you could create a form for creating both like so:
 
 <erb>
-<%= form_for :person, @person, :url => { :action => "create" } do |person_form| %>
+<%= form_for @person, :url => { :action => "create" } do |person_form| %>
   <%= person_form.text_field :name %>
   <%= fields_for @person.contact_detail do |contact_details_form| %>
     <%= contact_details_form.text_field :phone_number %>