ruby on rails - Nested form accepts_nested_attributes_for giving dynamic Array - Rails4 -

i working on rails4 nested form, accepts_nested_attributes_for can able generate nested form giving dynamic array the form when inspect form.

 <input type="text" name="event_venue[event_contact_details_attributes][1403763304978][name]" id="event_venue_event_contact_details_attributes_1403763304978_name" class="form-control"> 

but should be,

<input type="text" name="event_venue[event_contact_details_attributes][1][name]" id="event_venue_event_contact_details_attributes_1_name" class="form-control">

<div class="formwrapper">   <div class="col-md-6">     <div class="form-group">       <label for="exampleinputemail1">name</label>       <input type="text" name="event_venue[event_contact_details_attributes][1403764358820][name]" id="event_venue_event_contact_details_attributes_1403764358820_name" class="form-control">     </div>     <div class="form-group">       <label for="exampleinputemail1">phone</label>       <input type="text" name="event_venue[event_contact_details_attributes][1403764358820][telephone]" id="event_venue_event_contact_details_attributes_1403764358820_telephone" class="form-control">     </div>     <div class="form-group">       <label for="exampleinputemail1">email</label>       <input type="text" name="event_venue[event_contact_details_attributes][1403764358820][email]" id="event_venue_event_contact_details_attributes_1403764358820_email" class="form-control">     </div>     <div class="clearfix"></div>     <input type="hidden" value="false" name="event_venue[event_contact_details_attributes][1403764358820][_destroy]" id="event_venue_event_contact_details_attributes_1403764358820__destroy"><a onclick="remove_fields(this); return false;" href="#">remove</a>   </div> </div> 

can me out missing things...!!!

in first nested form set it's coming right,

<div class="formwrapper">   <div class="col-md-6">     <div class="form-group">       <label for="exampleinputemail1">name</label>       <input type="text" value="as" name="event_venue[event_contact_details_attributes][0][name]" id="event_venue_event_contact_details_attributes_0_name" class="form-control">     </div>     <div class="form-group">       <label for="exampleinputemail1">phone</label>       <input type="text" value="as" name="event_venue[event_contact_details_attributes][0][telephone]" id="event_venue_event_contact_details_attributes_0_telephone" class="form-control">     </div>     <div class="form-group">       <label for="exampleinputemail1">email</label>       <input type="text" value="as" name="event_venue[event_contact_details_attributes][0][email]" id="event_venue_event_contact_details_attributes_0_email" class="form-control">     </div>     <div class="clearfix"></div>     <input type="hidden" value="false" name="event_venue[event_contact_details_attributes][0][_destroy]" id="event_venue_event_contact_details_attributes_0__destroy"><a onclick="remove_fields(this); return false;" href="#">remove</a>   </div> </div> 

event venue model,

has_many :event_contact_details, :dependent => :destroy     accepts_nested_attributes_for :event_contact_details, allow_destroy: true 

controller,

def new     @event_venue = eventvenue.new     @event_venue.event_contact_details.build   end 

form,

<%= f.fields_for :event_contact_details |builder| %>             <%= render :partial => 'event_venues/event_contact_detail_fields',                         :locals => { :f => builder } %>           <% end %>            <p><%= link_to_add_fields "add more", f, :event_contact_details  %></p>