Topic: create a profile entry for the user

hi, I am learning rails and i got a big problem,

class ProfilesController < ApplicationController
  before_filter :authenticate_user!

  def new
    @profile = Profile.new
  end

  def create
    @profile = current_user.profile.create(params[:profile])
  end
end

I have a form witch submit data to the create method. When the create method is called an error occure saying that .create is not a method of the object nil.
there is a profile model and all routes are setted

## the profile class
class Profile < ActiveRecord::Base

  attr_accessible :city, :country, :first_name, :last_name, :phone, :province
  
  belongs_to :User

end

## the routes

 resource :profile

current_user.profile return nil because the current_user doesn't have a profile yet. How can i create a profile for this user