Add a profile model with User model - Edit Problem

Hi there, I used restful authentication to generate the authenticated system, but i still want to add a profile model as a part of user model. So between user & profile I use has_one association to connect them. Create - OK But when i want to edit someone's profile, the data not update in sql. my user model is like this: has_one :profile attr_accessible :login, :email, :password, :password_confirmation def profile_attributes=(profile_attributes)     profile_attributes do |attributes|        profile = profile.detect {|p| == attributes[:id].to_i}        profile.attributes = attributes     end   end My Profile model is like this: belongs_to :user The migration has the user_id foreign_key set up. In the view/user/edit.html.erb, i wrote enclosed codes: <% form_for :user, :url => user_url(@user), :html => { :method => :put } do |f| %>   <p>Email:<br /><%= f.text_field :email, :size => 60 %></p>   <% fields_for "user[profile_attributes]", @user.profile do | p_form| %>     <p>      Name: <%= p_form.text_field :name, :index => nil %>     </p>     <p>      Gender: <%= p_form.text_field :gender, :index => nil %>     </p>     <p>       Birthday: <%= p_form.text_field :birth_on, :index => nil %>     </p>     <p>       Place: <%= p_form.text_field :place, :index => nil %>     </p>     <p>       About Me: <%= p_form.text_field :about_me, :index => nil %>     </p>     <%= p_form.hidden_field :id, :index => nil %>   <% end %> <%= submit_tag 'Update' %> <% end %> When I click update button, error says: Couldn't find Profile without an ID Or Can't mass-assign in a protected attributes in the development log. Can anyone help me?

You might want to post this to the Ruby-on-Rails-Talk group as this is the newsgroup for the development of the Rails framework itself.

Thanks Matt. I've already done this.