<% form_remote_tag(:update => :search_results_content,
:loading => "openSearchResults()",
:url => { :controller => :geocoder, :action => :search }) do %>
<%= text_field_tag :query, params[:query] %>
<% end %>
examples: 'Alkmaar', 'Regent Street, Cambridge', 'CB2 5AQ',
or 'post offices near Lünen'
more examples...