nested partials parameters

Hi

I have presently the following view :

<div>   <p><%= f.label :tz_area, I18n.t("label.form.tz_area") %></p/>   <div id="tz_area_selector">     <p>                    <%= f.label :timezone, I18n.t("label.form.timezone") %><br />         <%= f.time_zone_select :time_zone, /"#{@instructor.tz_area}"/, :default => @instructor.time_zone %>     </p>   </div> </div>

As I need to modify the time_zone_select when another field is modified, I'll use an Ajax request , so I am using a partial and replaced this code with

<div>   <p><%= f.label :tz_area, I18n.t("label.form.tz_area") %></p/>

  <div id="tz_area_selector">               <%= render :partial => "tz_selector", :locals => { :f => f } %>   </div>

</div>

the Ajax request is performed, and my controller try to replace the partial ....     render :update do |page|       page.replace_html 'time_zone_selector', :partial => "time_zone_selector", :locals => { :f => f }     end

but obviously I get an error ,as f is undefined :

NameError (undefined local variable or method `f'

how can I replace this piece of the form ?

thanks

erwin