diff --git a/app/controllers/user_admin_controller.rb b/app/controllers/user_admin_controller.rb
--- a/app/controllers/user_admin_controller.rb
+++ b/app/controllers/user_admin_controller.rb
@@ -16,6 +16,16 @@
     @hidden_columns = ['hashed_password', 'salt', 'created_at', 'updated_at']
   end
 
+  def active
+    sessions = ActiveRecord::SessionStore::Session.find(:all, :conditions => ["updated_at >= ?", 60.minutes.ago])
+    @users = []
+    sessions.each do |session|
+      if session.data[:user_id]
+        @users << User.find(session.data[:user_id])
+      end
+    end
+  end
+
   def show
     @user = User.find(params[:id])
   end
diff --git a/app/models/user.rb b/app/models/user.rb
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -125,6 +125,9 @@
       begin
         if self.site==nil
           self.site = Site.find_by_name('default')
+          if self.site==nil
+            self.site = Site.find(1)  # when 'default has be renamed'
+          end
         end
       rescue
       end
diff --git a/app/views/main/login.html.haml b/app/views/main/login.html.haml
--- a/app/views/main/login.html.haml
+++ b/app/views/main/login.html.haml
@@ -19,7 +19,7 @@
     %b= flash[:notice]
     %hr/
 
-  %div{ :style => "border: solid 1px gray; padding: 2px; background: #f0f0f0;"}
+  %div{ :style => "border: solid 1px gray; padding: 4px; background: #eeeeff;"}
     - form_tag :controller => 'login', :action => 'login' do
       %table
         %tr
diff --git a/app/views/test/_test_request.html.haml b/app/views/test/_test_request.html.haml
--- a/app/views/test/_test_request.html.haml
+++ b/app/views/test/_test_request.html.haml
@@ -7,7 +7,10 @@
     - else
       (n/a)
   %td{:align => "center"}
-    = test_request.submission.number
+    - if test_request.submission
+      = test_request.submission.number
+    - else
+      n/a
   %td{:align => "center"}
     = test_request.status_str
   %td{:align => "center"}
diff --git a/app/views/user_admin/active.html.haml b/app/views/user_admin/active.html.haml
new file mode 100644
--- /dev/null
+++ b/app/views/user_admin/active.html.haml
@@ -0,0 +1,19 @@
+%h1 Active users
+
+%i
+  I.e., those users that interacts with the system with in the last 60 minutes.
+%br/
+
+= link_to '[go back to index]', :action => 'index'
+
+%table
+  %tr
+    %th #
+    %th login
+    %th full name
+  - counter = 0
+  - for user in @users
+    %tr
+      %td= counter += 1
+      %td= user.login
+      %td= user.full_name
diff --git a/app/views/user_admin/list.rhtml b/app/views/user_admin/list.rhtml
--- a/app/views/user_admin/list.rhtml
+++ b/app/views/user_admin/list.rhtml
@@ -25,8 +25,14 @@
 <% form_tag({:action => 'import'}, :multipart => true) do %>
   File: <%= file_field_tag 'file' %> <%= submit_tag 'Import' %>
 <% end %>
+<br/>
+<b>What else: </b>
+<%= link_to '[New user]', :action => 'new' %>
+<%= link_to '[New list of users]', :action => 'new_list' %>
+<%= link_to '[View active users]', :action => 'active' %>
 
 </div>
+
 <table>
   <tr>
   <% for column in User.content_columns %>
diff --git a/config/locales/th.rb b/config/locales/th.rb
--- a/config/locales/th.rb
+++ b/config/locales/th.rb
@@ -1,3 +1,7 @@
+# Thai translation for Ruby on Rails
+# original by Prem Sichanugrist (s@sikachu.com/sikandsak@gmail.com)
+# activerecord keys fixed by Jittat Fakcharoenphol (jittat@gmail.com)
+
 { 
   :'th' => {
     :date => {
@@ -66,6 +70,22 @@
           :format => '%n %u'
         }
       },
+      :human => {
+        :format => {
+          :precision => 1,
+          :delimiter => ''
+        },
+       :storage_units => {
+         :format => "%n %u",
+         :units => {
+           :byte => "B",
+           :kb   => "KB",
+           :mb   => "MB",
+           :gb   => "GB",
+           :tb   => "TB",
+         }
+       }
+      },
     },
 
     # Active Record
diff --git a/db/migrate/20081215012843_change_user_login_string_limit.rb b/db/migrate/20081215012843_change_user_login_string_limit.rb
--- a/db/migrate/20081215012843_change_user_login_string_limit.rb
+++ b/db/migrate/20081215012843_change_user_login_string_limit.rb
@@ -4,6 +4,6 @@
   end
 
   def self.down
-    execute "ALTER TABLE `users` CHANGE `login` `login` VARCHAR( 10 )"
+    # don't have to revert
   end
 end
diff --git a/public/stylesheets/application.css b/public/stylesheets/application.css
--- a/public/stylesheets/application.css
+++ b/public/stylesheets/application.css
@@ -1,31 +1,66 @@
-/* Normal text */
+/* Main Default */
 body {
+    background: white url(../images/topbg.jpg) repeat-x top center;
     font-size: 13px;
-    font-family: "Sans Serif";
+    font-family: Tahoma, "sans-serif";
+    margin: 10px;
+    padding: 10px;
+}
+
+/* Form Font */
+input {
+    font-family: Tahoma, "sans-serif";
+}
+
+/* Heading 1/2 */
+h1 {
+    font-size: 24px;
+    color: #334488;
+    line-height: 2em;
+}
+
+h2 {
+    font-size: 18px;
+    color: #5566bb;
+    line-height: 1.5em;
+}
+
+/* Bar Line Color and Thickness */ 
+hr {
+    border-top: 1px solid #dddddd;
+    border-bottom: 1px solid #eeeeee;
+}
+
+/* Link + Anchor Color */
+a, a:link, a:visited {
+    color: #6666cc;
+    text-decoration: none;
+}
+
+a:hover, a:focus {
+    color: #111166;
+    text-decoration: none;
 }
 
 /* This is the main menu bad*/
 div.userbar { 
-    border-top: thin solid grey;
-    border-bottom: thin solid grey;
+    line-height: 1.5em;
     text-align: right;
     font-size: 12px;
 }
 
 /* This is the top bar, displaying user's full name */
 div.title {
-    font-size: 12px;
-    background: #ddffdd;
-    border: 1px solid black;
-    padding: 2px;
-    margin-top: 3px;
-    margin-bottom: 5px;
+    // background: #ddddff;
+    // border: 1px dashed blue;
+    padding: 10px 0px;
+    line-height: 1.5em;
+    font-size: 13px;
 }
 
 div.title span.contest-over-msg {
     font-size: 15px;
     color: red;
-    font-weight: bold;
 }
 
 div.title table {
@@ -35,27 +70,36 @@
 div.title td.left-col {
     text-align: left;
     vertical-align: top;
+    color: #444444;
 }
 
 div.title td.right-col {
     text-align: right;
     vertical-align: top;
+    font-size: 14px;
+    font-weight: bold;
+    color: #116699;
 }
 
 /* Standard table with header and rows with alternating background */
 table.info {
-    border: 1px solid black;
+    margin: 10px 0;
+    border: 1px solid #666666;
     border-collapse: collapse;
     font-size: 12px;
 }
 
 table.info th {
-    border: 1px solid black;
+    border: 1px solid #666666;
+    line-height: 1.5em;
+    padding: 0 0.5em;
 }
 
 table.info td {
-    border-left: 1px solid black;
-    border-right: 1px solid black;
+    border-left: 1px solid #666666;
+    border-right: 1px solid #666666;
+    line-height: 1.5em;
+    padding: 0 0.5em;
 }
 
 tr.info-head {
@@ -64,29 +108,30 @@
 }
 
 tr.info-odd {
-    background: #dddddd;
+    background: #eeeeee;
 }
 
 tr.info-even {
-    background: #f0f0f0;
+    background: #f9f9f9;
 }
 
 /*******************************
  [Main]
 ********************************/
 div.submitbox {
-    border: thin solid black;
+    background: #eeeeff;
+    border: 1px dotted #99aaee;
     padding: 5px;
-    color: white;
-    background-color: #777777;
+    margin: 10px 0px;
+    color: black;
     font-weight: bold;
     font-size: 13px;
 }
 
 div.errorExplanation {
-    border: 1px dashed black;
-    color: black;
-    padding: 5px;
+    border: 1px dotted gray;
+    color: #bb2222;
+    padding: 5px 15px 5px 15px;
     margin-bottom: 5px;
     background-color: white;
 }
@@ -124,9 +169,10 @@
 div.task-menu {
     text-align: center;
     font-size: 13px;
+    line-height: 1.75em;
     font-weight: bold;
-    border-top: 1px solid black;
-    border-bottom: 1px solid black;
+    border-top: 1px dashed gray;
+    border-bottom: 1px dashed gray;
     margin-top: 2px;
     margin-bottom: 4px;
 }
@@ -135,9 +181,10 @@
  [Submission]
 ********************************/
 table.taskdesc {
-    border: 1px solid black;
+    border: 2px solid #dddddd;
     border-collapse: collapse;
-    width: 95%;
+    margin: 10px auto;
+    width: 90%;
     font-size: 13px;
 }
 
@@ -146,11 +193,12 @@
 }
 
 table.taskdesc tr.name {
-    border: 1px solid black;
-    background: #aaaaaa;
-    color: white;
+    border: 2px solid #dddddd;
+    background: #dddddd;
+    color: #333333;
     font-weight: bold;
     font-size: 14px;
+    line-height: 1.5em;
     text-align: center;
 }
 
@@ -167,20 +215,20 @@
 }
 
 /**********************
- [Announcement]
+   Announcement
 ***********************/
 
 div.announcementbox {
-    margin-top: 10px;
-    margin-bottom: 10px;
-    background: green;
+    margin: 10px 0px;
+    background: #bbddee;
     padding: 1px;
 }
 
 div.announcementbox span.title {
     font-weight: bold;
-    color: white;
+    color: #224455;
     padding-left: 10px;
+    line-height: 1.6em;
 }
 
 div.announcement {
@@ -202,30 +250,44 @@
 }
 
 /******************
-  [Messages
+   Messages
 ******************/
 
 div.message {
-    padding-top: 5px;
-    padding-left: 10px;
+    margin: 10px 0 0;
+}
+
+div.message div.message {
+    margin: 0 0 0 30px;
 }
 
 div.message div.body {
-    border: 1px solid green;
-    background: #eeffee;
+    border: 2px solid #dddddd;
+    background: #fff8f8;
     padding-left: 5px;
 }
 
 div.message div.reply-body {
-    border: 1px solid black;
-    background: #ffeeee;
+    border: 2px solid #bbbbbb;
+    background: #fffff8;
     padding-left: 5px;
 }
 
 div.message div.stat {
     font-size: 10px;
-    color: white;
-    background: green;
+    line-height: 1.75em;
+    padding: 0 5px;
+    color: #333333;
+    background: #dddddd;
+    font-weight: bold;
+}
+
+div.message div.message div.stat {
+    font-size: 10px;
+    line-height: 1.75em;
+    padding: 0 5px;
+    color: #444444;
+    background: #bbbbbb;
     font-weight: bold;
 }
 
@@ -234,17 +296,17 @@
 ********************/
 div.contest-title {
     color: white;
-    background: #007700;
     text-align: center;
-    padding: 5px;
+    line-height: 2em;
 }
 
 div.registration-desc {
-    margin-top: 5px;
-    margin-bottom: 5px;
-    border: solid 1px gray; 
-    padding: 10px; 
-    background: #f0f0f0;
+    border: 1px dotted gray;
+    background: #f5f5f5;
+    padding: 5px;
+    margin: 10px 0;
+    font-size: 12px;
+    line-height: 1.5em;
 }
 
 /********************
@@ -252,9 +314,10 @@
 ********************/
 
 div.test-desc {
-    border: solid 1px gray; 
-    background: #f0f0f0;
+    border: 1px dotted gray; 
+    background: #f5f5f5;
     padding: 5px;
+    margin: 10px 0;
     font-size: 12px;
-    margin-bottom: 5px;
+    line-height: 1.5em;
 }