Mass-assigment attr_accessable

controller.rb

class UsersController < ApplicationController
  respond_with :html
  def create
    @user = User.new(params[:user])
	
    if @user.save
      respond_with [:admin, @user], notice: "User succesfully created!"
    else
      redirect_to 'admin/users/new', alert: "User was not created: #{@user.errors.full_messages.join(',')}"
    end
  end
end

user.rb

class User < ActiveRecord::Base
  attr_accessible :admin

  def admin=(raw_value)
    is_admin = (raw_value == "1")
    self.write_attribute(:admin, is_admin)
  end
end