anchor.diff:  </div>
   
   <%= javascript_tag "var users = #{IndexHelper.users_to_hash(session).to_json};" %>
  -<%= javascript_tag "var cf_users = #{Hash[User.all.map{|u| [u.id, u.codeforces]}].to_json};" %>
  +<%= javascript_tag "var cf_users = #{Hash[users.map{|u| [u.id, u.codeforces]}].to_json};" %>
   <script type="text/javascript">
   $(function()
   {
  
positive.code: 						<% when 1 %> <!-- Codeforces -->
  							<tr class="codeforces-problem">
  								<td><a target="_blank" href="http://codeforces.com/">Codeforces</a></td>
  								<td class="problem-format" data-phandle="<%= pb.handle %>">Unknown Problem</td>
  								<td><%= ProblemsetsHelper.difficulty_to_s(pb.difficulty) %></td>
  								<% users.each do |u| %>
  									<td class="user-submission" data-user="<%= u.id %>"><span title="Not tried">-</span></td>
  
negative.code: 						   when 0 %> <!-- UVa -->
  							<tr class="uva-problem">
  								<td><a target="_blank" href="https://uva.onlinejudge.org/">UVa Onlinejudge</a></td>
  								<td class="problem-format" data-pnum="<%= pb.handle %>"><%= pb.handle %> - Unknown Problem</td>
  								<td><%= ProblemsetsHelper.difficulty_to_s(pb.difficulty) %></td>
  								<% users.each do |u| %>
  									<td class="user-submission" data-user="<%= u.id %>"><span title="Not tried">-</span></td>
  