diff --git a/main/forum/iframe_thread.php b/main/forum/iframe_thread.php
index 82b9168033..53784a78c3 100644
--- a/main/forum/iframe_thread.php
+++ b/main/forum/iframe_thread.php
@@ -105,12 +105,13 @@ echo "<table width=\"100%\" cellspacing=\"5\" border=\"0\">";
 while ($row = Database::fetch_array($result)) {
     echo "<tr>";
     echo "<td rowspan=\"2\" class=\"forum_message_left\">";
+    $username = $row['username'];
     if ($row['user_id']=='0') {
         $name = $row['poster_name'];
     } else {
         $name = api_get_person_name($row['firstname'], $row['lastname']);
     }
-    echo $name.'<br />';
+    echo $name." ($username)<br />";
     echo api_convert_and_format_date($row['post_date']).'<br /><br />';
 
     echo "</td>";
diff --git a/main/forum/index.php b/main/forum/index.php
index e82d181dbb..13b8ff4f58 100644
--- a/main/forum/index.php
+++ b/main/forum/index.php
@@ -13,7 +13,7 @@
  *                      multiple forums per group
  * - sticky messages
  * - new view option: nested view
- * - quoting a message
+ * - quoting a message 
  *
  * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
  * @copyright Ghent University
@@ -392,14 +392,17 @@ if (is_array($forum_categories_list)) {
                         if ($forum['last_poster_name'] != '') {
                             $name = $forum['last_poster_name'];
                             $poster_id = 0;
+                            $username = "";
                         } else {
                             $name = api_get_person_name($forum['last_poster_firstname'], $forum['last_poster_lastname']);
                             $poster_id = $forum['last_poster_id'];
+                            $userinfo = api_get_user_info($poster_id);  // 
+                            $username = " (".$userinfo['username'].")";  // 
                         }
                         echo '<td nowrap="nowrap">';
 
                         if (!empty($forum['last_post_id'])) {
-                            echo api_convert_and_format_date($forum['last_post_date']).'<br /> '.get_lang('By').' '.display_user_link($poster_id, $name);
+                            echo api_convert_and_format_date($forum['last_post_date']).'<br /> '.get_lang('By').' '.display_user_link($poster_id, $name.$username); // 
                         }
                         echo '</td>';
                         echo '<td nowrap="nowrap" align="center">';
diff --git a/main/forum/viewforum.php b/main/forum/viewforum.php
index 293964e094..6523ed9e01 100644
--- a/main/forum/viewforum.php
+++ b/main/forum/viewforum.php
@@ -354,39 +354,47 @@ if (is_array($threads)) {
             echo '<td>';
             echo '<a href="viewthread.php?'.api_get_cidreq().'&amp;gidReq='.Security::remove_XSS($_GET['gidReq']).'&amp;gradebook='.Security::remove_XSS($_GET['gradebook']).'&amp;forum='.Security::remove_XSS($my_forum).'&amp;origin='.$origin.'&amp;thread='.$row['thread_id'].$origin_string.'&amp;search='.Security::remove_XSS(urlencode($my_search)).'" '.class_visible_invisible($row['visibility']).'>'.prepare4display($row['thread_title']).'</a></td>';
             echo '<td>'.$row['thread_replies'].'</td>';
-            if ($row['user_id'] == '0') {
-                $name = prepare4display($row['thread_poster_name']);
-            } else {
-                $name = api_get_person_name($row['firstname'], $row['lastname']);
-            }
             echo '<td>'.$row['thread_views'].'</td>';
+            // display the author name
+            $tab_poster_info = api_get_user_info($row['user_id']);
+            $poster_username = " (".$tab_poster_info['username'].")";
+            if ($origin != 'learnpath') {
+                echo '<td>'.display_user_link($row['user_id'], api_get_person_name($row['firstname'], $row['lastname']).$poster_username).'</td>';
+            } else {
+                echo '<td>'.api_get_person_name($row['firstname'], $row['lastname']).'$poster_username</td>';
+            }            
+            // display the last post name
+//            if ($row['user_id'] == '0') {
+//                $name = prepare4display($row['thread_poster_name']);
+//            } else {
+//                $name = api_get_person_name($row['firstname'], $row['lastname']);
+//            } 
+            
             if ($row['last_poster_user_id'] == '0') {
                 $name = $row['poster_name'];
+                $last_poster_username = "";
             } else {
                 $name = api_get_person_name($row['last_poster_firstname'], $row['last_poster_lastname']);
+                $tab_last_poster_info = api_get_user_info($row['last_poster_user_id']);
+                $last_poster_username = " (".$tab_last_poster_info['username'].")";
             }
-
-            if ($origin != 'learnpath') {
-                echo '<td>'.display_user_link($row['user_id'], api_get_person_name($row['firstname'], $row['lastname'])).'</td>';
-            } else {
-                echo '<td>'.api_get_person_name($row['firstname'], $row['lastname']).'</td>';
-            }
-
             // If the last post is invisible and it is not the teacher who is looking then we have to find the last visible post of the thread.
             if (($row['visible'] == '1' OR api_is_allowed_to_edit(false, true)) && $origin != 'learnpath') {
-                $last_post = api_convert_and_format_date($row['thread_date']).' '.get_lang('By').' '.display_user_link($row['last_poster_user_id'], $name);
+                $last_post = api_convert_and_format_date($row['thread_date']).' '.get_lang('By').' '.display_user_link($row['last_poster_user_id'], $name.$last_poster_username);
             } elseif ($origin != 'learnpath') {
-                $last_post_sql = "SELECT post.*, user.firstname, user.lastname FROM $table_posts post, $table_users user WHERE post.poster_id=user.user_id AND visible='1' AND thread_id='".$row['thread_id']."' ORDER BY post_id DESC";
+                $last_post_sql = "SELECT post.*, user.firstname, user.lastname, user.username FROM $table_posts post, $table_users user WHERE post.poster_id=user.user_id AND visible='1' AND thread_id='".$row['thread_id']."' AND post.c_id=".api_get_course_int_id()." ORDER BY post_id DESC";
                 $last_post_result = Database::query($last_post_sql);
                 $last_post_row = Database::fetch_array($last_post_result);
                 $name = api_get_person_name($last_post_row['firstname'], $last_post_row['lastname']);
-                $last_post = api_convert_and_format_date($last_post_row['post_date']).' '.get_lang('By').' '.display_user_link($last_post_row['poster_id'], $name);
+                $last_post_info_username = " (".$last_post_row['username'].")";
+                $last_post = api_convert_and_format_date($last_post_row['post_date']).' '.get_lang('By').' '.display_user_link($last_post_row['poster_id'], $name.$last_post_info_username);
             } else {
-                $last_post_sql = "SELECT post.*, user.firstname, user.lastname FROM $table_posts post, $table_users user WHERE post.poster_id=user.user_id AND visible='1' AND thread_id='".$row['thread_id']."' ORDER BY post_id DESC";
+                $last_post_sql = "SELECT post.*, user.firstname, user.lastname, user.username FROM $table_posts post, $table_users user WHERE post.poster_id=user.user_id AND visible='1' AND thread_id='".$row['thread_id']."' AND post.c_id=".api_get_course_int_id()." ORDER BY post_id DESC";
                 $last_post_result = Database::query($last_post_sql);
                 $last_post_row = Database::fetch_array($last_post_result);
+                $last_post_info_username = " (".$last_post_row['username'].")";
                 $name = api_get_person_name($last_post_row['firstname'], $last_post_row['lastname']);
-                $last_post = api_convert_and_format_date($last_post_row['post_date']).' '.get_lang('By').' '.$name;
+                $last_post = api_convert_and_format_date($last_post_row['post_date']).' '.get_lang('By').' '.$name.$last_post_info_username;
             }
 
             echo '<td>'.$last_post.'</td>';
diff --git a/main/forum/viewthread_flat.inc.php b/main/forum/viewthread_flat.inc.php
index 7faaee2651..a33dc5cb25 100644
--- a/main/forum/viewthread_flat.inc.php
+++ b/main/forum/viewthread_flat.inc.php
@@ -38,13 +38,15 @@ if (isset($current_thread['thread_id'])){
         } else {
             $name = api_get_person_name($row['firstname'], $row['lastname']);
         }
+        $username = $row['username'];   // 
+        
         if ($origin!='learnpath') {
             if (api_get_course_setting('allow_user_image_forum')) {
                 echo '<br />'.display_user_image($row['user_id'],$name).'<br />';
             }
-            echo display_user_link($row['user_id'], $name).'<br />';
+            echo display_user_link($row['user_id'], $name." ($username)").'<br />';
         } else {
-            echo $name. '<br />';
+            echo $name. ' ('.$username.')<br />';
         }
 
         $group_id = api_get_group_id();
diff --git a/main/forum/viewthread_nested.inc.php b/main/forum/viewthread_nested.inc.php
index 6228f5d29a..8b0d235015 100644
--- a/main/forum/viewthread_nested.inc.php
+++ b/main/forum/viewthread_nested.inc.php
@@ -47,6 +47,8 @@ foreach ($rows as $post) {
     echo "<table width=\"100%\"  class=\"post\" cellspacing=\"5\" border=\"0\">";
     echo "<tr>";
     echo "<td rowspan=\"3\" class=\"$leftclass\">";
+
+    $username = $post['username']; // 
     if ($post['user_id']=='0') {
         $name=$post['poster_name'];
     } else {
@@ -55,7 +57,7 @@ foreach ($rows as $post) {
     if (api_get_course_setting('allow_user_image_forum')) {
         echo '<br />'.display_user_image($post['user_id'],$name,$origin).'<br />';
     }
-    echo display_user_link($post['user_id'], $name, $origin).'<br />';
+    echo display_user_link($post['user_id'], $name." ($username)", $origin)."<br />";
     echo api_convert_and_format_date($post['post_date']).'<br /><br />';
     // get attach id
     $attachment_list=get_attachment($post['post_id']);
diff --git a/main/forum/viewthread_threaded.inc.php b/main/forum/viewthread_threaded.inc.php
index 701f56221b..91d4b66a54 100644
--- a/main/forum/viewthread_threaded.inc.php
+++ b/main/forum/viewthread_threaded.inc.php
@@ -158,6 +158,7 @@ unset($whatsnew_post_info[$current_forum['forum_id']][$current_thread['thread_id
 echo "<table width=\"100%\"  class=\"forum_table\"  cellspacing=\"5\" border=\"0\">";
 echo "<tr>";
 echo "<td rowspan=\"3\" class=\"$leftclass\">";
+$username = $rows[$display_post_id]['username'];
 if ($rows[$display_post_id]['user_id']=='0') {
     $name=prepare4display($rows[$display_post_id]['poster_name']);
 } else {
@@ -165,7 +166,7 @@ if ($rows[$display_post_id]['user_id']=='0') {
 }
 
 if (api_get_course_setting('allow_user_image_forum')) {echo '<br />'.display_user_image($rows[$display_post_id]['user_id'],$name, $origin).'<br />';	}
-echo display_user_link($rows[$display_post_id]['user_id'], $name, $origin).'<br />';
+echo display_user_link($rows[$display_post_id]['user_id'], $name." ($username)", $origin)."<br />";
 echo api_convert_and_format_date($rows[$display_post_id]['post_date']).'<br /><br />';
 // get attach id
 $attachment_list=get_attachment($display_post_id);