app/views/layouts/_product_search.html.erb
<%= form_for search_product, :html => {:class => 'search'} do %>
<div class="field search">
<span class="icon-search"></span>
<%= text_field_tag 'q', nil , :class => 'input-search text', :id => 'term' %>
<%= submit_tag 'Go', :class => 'button spade' %>
</div>
<% end %>