Dynamic Drop Down Submit problem

Hi all,

I have a little bit problem with my code here. basically, i want to have a drop down list, and if i select one value of the drop down list, the value of the text field that i have will change its value.

what i have done is to use observe field to dynamically update my text field. however, when i am pressing the submit button, it doesnt want to read the value of the text field. anyone knows what happen?

here is my code:

chapter controllers: def upload     @chapter = Chapter.new     @uploads = Book.find(:all)

  def get_chapter_number     @books= Book.find(:first,                       :conditions => ["title = ?", params["title"]])     render :layout => false   end end

views for upload: <%= javascript_include_tag "prototype" %> <% form_for (:chapter, @chapter, :url=>{:action => "uploadFile"}, :html => {:multipart => true}) do |f| -%>

            <label class="required">series title:</label>             <select name="upload[title]" id="upload[title]">             <% @uploads.each do |upload| %>               <option value="<%= upload.title %>">                 <%= upload.title %>               </option>             <% end %>             </select>

            <label class="required"> chapter: </label>             <div id="chapter_container">             </div>

            <%= observe_field("upload [title]", :update=>"chapter_container", :url=>{:action => "get_chapter_number"}, :with => 'title', :on=>"changed") %>

             <%= submit_tag 'Upload', :class => "submit" %>

views for get_chapter_number: <input type="text" id="upload_number_of_chapters" name="upload [number_of_chapters]" value= <%= @books.number_of_chapters + 1 %> size = "30" />

that code works fine.. if i select the value of the drop down list, it will dynamically update the text field. however, when i press the submit button, it doesnt read the value of the text field that being updated. any suggestion or help?

thanks in advance,

prawira

any1 got clue here?