Form Design issue - How to handle a parent association input..

I have an Event Model with a parent Place association

class Event < ActiveRecord::Base   belongs_to :place   accepts_nested_attributes_for :place   attr_accessible :place_attributes

In a new event registration form, the user should have the choice to : - select from an existing Place - enter a new Place in a nested form

= simple_form_for @event     = f.association :place, :collection => Place.all(:order => 'label'), :prompt => "Choose an Place", :label => false ..    = f.simple_fields_for :place do |pf|            #geolocation.form-inputs                   = pf.simple_fields_for :geolocation do |g|                       = render "backoffice/places/ geolocation_fields", :f => g

should I manage that with a jQuery script ? - when user select a place , it will clear the nested place form - when user enter data in the nested place form, it will reinitiate the place select

how can I manage the duplicated attribute param ? ( should the js script add/remove the corresponding html elements ?) I'm a little bit lost in translation.....