子模型更新时发生批量分配错误

<% form_for(@service)  do |service| %>
<%= fields_for :contact_info do |c| %>
<p>
  Contact Person: <%= c.text_field :contactPerson %>
</p>
<p>
  Contact Number: <%= c.text_field :contactNumber %>
</p>
<% end %>
<p>
  Issue: <%= service.text_field :issue, :rows => 3 %>
</p>
<p>
  Urgency: <%= service.text_field :urgency %>
</p>
<%= submit_tag \"Update\" %> 
<% end %>

class ContactInfo < ActiveRecord::Base
  has_many :services

  attr_accessible :contactPerson, :contactNumber
end

 class Service < ActiveRecord::Base
 belongs_to :user

 has_one :contact_info
 accepts_nested_attributes_for :contact_info, :allow_destroy => true

 attr_accessible :issue, :urgency, :contact_info_attributes, :group, :member

 end

# services_controller.rb

def update
  @service = Service.find(params[:id])
  if @service.update_attributes(params[:service]) && @service.update_attributes(params[:contact_info])
   redirect_to service_path(@service) 
  else
    redirect_to edit
  end
end

Parameters: {\"utf8\"=>\"✓\", \"authenticity_token\"=>\"ykJt08tkHSzoYgyQu11lnKms1BZ+vM2i/Q0ZOoYDxks=\", \"contact_info\"=>{\"contactPerson\"=>\"Jmes Jor\", \"contactNumber\"=>\"3726262\"}, \"service\"=>{\"issue\"=>\"My house is flooded.\", \"urgency\"=>\"1\"}, \"commit\"=>\"Update\", \"id\"=>\"46\"}
Service Load (0.8ms)  SELECT \"services\".* FROM \"services\" WHERE \"services\".\"id\" = 46 LIMIT 1
WARNING: Can\'t mass-assign protected attributes: contactPerson, contactNumber