diff --git a/app/views/users/_user_activities.html.erb b/app/views/users/_user_activities.html.erb
index bbef67e6d..9eefbd1f1 100644
--- a/app/views/users/_user_activities.html.erb
+++ b/app/views/users/_user_activities.html.erb
@@ -11,7 +11,7 @@
     .ke-inline-block{display: none;}
     div.ke-container{float:left;}
 </style>
-<% first_user_activity = user_activities.first.id %>
+<% first_user_activity = user_activities.first.id unless user_activities.first.nil? %>
 <% user_activities.each do |user_activity|
   if user_activities %>
         <script>
@@ -31,10 +31,10 @@
                 }
             }
 
-            function expand_reply_input(id) {
-                $(id).toggle();
-            }
-
+            function expand_reply_input(id) {
+                $(id).toggle();
+            }
+
             $(function() {
                 init_KindEditor_data(<%= user_activity.id%>,"30px","85%");
             });
@@ -45,22 +45,22 @@
             <% if act  %>
                 <% case user_activity.act_type.to_s %>
                 <% when 'HomeworkCommon' %>
-                    <%= render :partial => 'course_homework', :locals => {:activity => act,:user_activity_id =>user_activity.id,:first_user_activity =>first_user_activity,:page => page} %>
+                    <%= render :partial => 'course_homework', :locals => {:activity => act,:user_activity_id =>user_activity.id,:first_user_activity =>first_user_activity,:page => page} %>
                 <% when 'News' %>
-                    <%= render :partial => 'course_news', :locals => {:activity => act,:user_activity_id =>user_activity.id,:first_user_activity =>first_user_activity,:page => page} %>
+                    <%= render :partial => 'course_news', :locals => {:activity => act,:user_activity_id =>user_activity.id,:first_user_activity =>first_user_activity,:page => page} %>
                 <% when 'Message'%>
-                    <%= render :partial => 'course_message', :locals => {:activity => act,:user_activity_id =>user_activity.id,:first_user_activity =>first_user_activity,:page => page} %>
+                    <%= render :partial => 'course_message', :locals => {:activity => act,:user_activity_id =>user_activity.id,:first_user_activity =>first_user_activity,:page => page} %>
                 <% when 'Poll' %>
-                    <%= render :partial => 'course_poll', :locals => {:activity => act, :user_activity_id => user_activity.id,:first_user_activity =>first_user_activity,:page => page} %>
+                    <%= render :partial => 'course_poll', :locals => {:activity => act, :user_activity_id => user_activity.id,:first_user_activity =>first_user_activity,:page => page} %>
                 <% end %>
             <% end %>
         <% when 'Project' %>
             <% if act  %>
                 <% case user_activity.act_type.to_s %>
                 <% when 'Issue' %>
-                    <%= render :partial => 'project_issue', :locals => {:activity => act,:user_activity_id =>user_activity.id,:first_user_activity =>first_user_activity,:page => page} %>
+                    <%= render :partial => 'project_issue', :locals => {:activity => act,:user_activity_id =>user_activity.id,:first_user_activity =>first_user_activity,:page => page} %>
                 <% when 'Message' %>
-                    <%= render :partial => 'project_message', :locals => {:activity => act,:user_activity_id =>user_activity.id,:first_user_activity =>first_user_activity,:page => page} %>
+                    <%= render :partial => 'project_message', :locals => {:activity => act,:user_activity_id =>user_activity.id,:first_user_activity =>first_user_activity,:page => page} %>
                 <% end %>
             <% end %>
         <% end %>