div disappearing when enclosed partial re-rendered

Below is controller code wherein asses gets called, and subsequently (re) renders the "hand' partial (which is enclosed in the view "play" (which is what was originally called to invoke this whole thing). It contains javascript to invoke the asses() method in the controller, below. However, when I invoke asses (from the javascript) the bot div disappears -- and I need it because I have javascript in application.js that is reading the json file created in asses() and replacing the innerHTML in the bot div.

Why does my bot div disappear when asses in the controller is invoked? Thanks, R.Vince

===== controllers/games_controller.rb

class GamesController < ApplicationController   skip_before_filter :verify_authenticity_token

  def play

  end

  def asses     # do some stuff then....     t = Time.now     @whowon = t.strftime("%H:%M:%S")     if outcome != 0       totplays = current_user.plays + 1       totwins = current_user.wins       if outcome > 0         totwins = totwins + 1         @whowon = @whowon << " -- you won!"       else         @whowon = @whowon << " -- you lost."       end       totpercent = totwins.to_f / totplays.to_f * 100       current_user.update_attributes(:plays => totplays, :wins => totwins, :percent => totpercent)     else       @whowon = @whowon << " -- Nobody won - tie!"     end

     x = User.find(:all, :conditions => ["percent is not null"], :limit => 10, :order => "percent DESC").collect {|p| [ p.username, p.percent]}     #puts x.to_json      File.open('public/json.dat', 'w') do |file|       file.puts x.to_json     end

     render :partial => 'hand' , :layout => 'application'   end end

===== views/games/_hand.html.erb

<center>   <%= current_user.username %> select your next play:<br>   <form action="/games/asses" method="post" name="playform">       <select id="play" name="play" onchange="document.playform.submit ();document.playform.reset()">         <option value=""></option>         <option value="1">Rock</option>         <option value="2">Paper</option>         <option value="3">Scissors</option>     </select>   </form>   <div id="outcome">     <%= @whowon || ' ' %>   </div> </center> <script type="text/javascript">   Effect.Fade("outcome", { duration: 5.0 }) </script>

===== views/games/play.html.erb

<% if current_user == nil %>   <% redirect_to root_url %> <% end %> <div id="top">   <%= render :partial => 'hand' %> </div> <div id="bot"> </div> <script type="text/javascript">   startClock("../json.dat" );   Effect.Fade("outcome", { duration: 5.0 }) </script>