anchor.diff:  
   <p>
   <% form_tag(:action => :leave_channel, :id => @channel) do %>
  -  <input type='submit' value='<%= "Leave channel"[:leave_channel] %>' />
  +  <input type='submit' value='<%= "Leave channel"[:leave_channel]%>' onclick='stop_ajax()' />
   <% end %>
   </p>
   
  
positive.code:               :frequency => wait_time,
                :url => { :controller => 'chat',
                          :action => 'user_is_typing',
                          :id => @channel })
  %>
  
negative.code: 			      	   :action => 'user_list',
  				   :id => @channel},
  			 :frequency => wait_time,
  			 :update => 'userlist',
                           :condition => 'stop_ajax_calls == false')
  %>
  
  <%= # poll server every wait_time seconds for new messages
  