Application_Form/app/models/seminar_user.rb

class SeminarUser
    include Mongoid::Document
    include Mongoid::Timestamps
    field :user_name
    field :password
    belongs_to :seminar_main
    # belongs_to :user
    # before_save do
    #     if self.new_record?
    #         self.user = User.find()
    #     end
    # end
end