gistfile1.rhtml

<!-- index.html.erb -->

<% form_tag search_path do %>
	<%= select :search, :state, State.all.collect { |m| [m.full_name, m.id] }.sort, {:prompt=>'Please Select...'} %>
	<%= observe_field(:state, :url => { :action => :update_city_menu },
                  :update => :city_field_div,
                  :with => :state
            ) %> 
	<div id="city_field_div"></div>
        <%= submit_tag 'Submit' %>
<% end %>