Rails 3 Switch menu reload page when change data

The use开发者_高级运维r can edit his account and has a menu to choose his community :

<%= form_for @user, :html => { :multipart => true } do |f| %>
    <%= f.collection_select :community_id, Community.find(:all,
    :include => :memberships,
    :conditions => ['memberships.user_id = ? and memberships.role > ?', @user.id, '0' ]),
    :id,
    :name,
    :style => "width: 200px;" %>
<% end %>

I would like to put this menu on the show page and give him the possibility to switch directly.

With rails 2, I used observe_field or :onchange => 'this.form.onsubmit()' and I don't know java…

<%= form_for @user, :remote => true do |f| %>
<%= f.collection_select :community_id,
Community.where('memberships.user_id = ? and memberships.role > ?', @user.id, '0').includes(:memberships), :id, :name,{},
:onchange => "this.form.submit();" %>   
<% end %>

Changed 'this.form.onsubmit() to 'this.form.submit()