This works except for one thing...if there's a value in placement.client_slot_id, it doesn't 'select' the value in the selection list. How can I get it to select the value that matches @placement.client_slot_id.name ?
view <span id="client_slot_id"> <%= select_tag 'placement', 'client_slot_id', :selected => @placement.client_slot.name %></span>
<%= observe_field( :placement_facility_id, :frequency => 0.5, :update => :client_slot_id, :url => { :controller => 'placements', :action => :lookup_client_slot }, :with => "'facility_id='+escape(value)") %>
controller def lookup_client_slot @client_slots = ClientSlot.find(:all, :conditions => ["facility_id = ?", params[:facility_id]] ).collect {|fac| [fac.name, fac.id]} render :inline => "<%= select 'placement', 'client_slot_id', @client_slots %>" end