gistfile1.rb

#FORM
%fieldset#organization{:style => "display:none"}
  %h3 
    Organization
  = f.fields_for :organisations do |org|
    .row
      .span5
        = org.input :name, :label => "<strong>Name of the Organization</strong>"
      .span5
        //= org.input :title, :label => "Your role"
    .row
      .span10
        = org.input :description, :as => :text, :label => "Description of the organization", :hint => "Give us a short description of your company or organizaiton."
    .row
      = org.link_to_remove "Remove this oranisation"
  = f.link_to_add "Add an organisation", :organisations
  %hr.prof_bar

#profile
class Profile < ActiveRecord::Base
  has_many :memberships
  has_many :organisations, :through => :memberships
#organisations
class Organisation < ActiveRecord::Base
  has_many :memberships
  has_many :members, :through => :memberships
#membership
class Membership < ActiveRecord::Base
  belongs_to :organisation
  belongs_to :profile
end