diff --git a/application/controllers/admin/participantsaction.php b/application/controllers/admin/participantsaction.php
index 873fd442bbb..60873cac1de 100644
--- a/application/controllers/admin/participantsaction.php
+++ b/application/controllers/admin/participantsaction.php
@@ -315,10 +315,17 @@ function getShareInfo_json()
 
             foreach ($records as $row)
             {
-                $oShared = User::model()->getName($row['share_uid']); //for conversion of uid to human readable names
+                //for conversion of uid to human readable names
+                $iShareUserId = $row['share_uid'];
+                if ($iShareUserId != 0) { 
+                    $oShared = User::model()->getName($iShareUserId); 
+                    $sSharename = $oShared[0]['full_name'];
+                } else {
+                    $sSharename = 'All users';
+                }
                 $owner = User::model()->getName($row['owner_uid']);
                 $aData->rows[$i]['id'] = $row['participant_id']."--".$row['share_uid']; //This is the unique combination per record
-                $aData->rows[$i]['cell'] = array($row['firstname'], $row['lastname'], $row['email'], $oShared[0]['full_name'], $row['share_uid'], $owner[0]['full_name'], $row['date_added'], $row['can_edit']);
+                $aData->rows[$i]['cell'] = array($row['firstname'], $row['lastname'], $row['email'], $sSharename, $row['share_uid'], $owner[0]['full_name'], $row['date_added'], $row['can_edit']);
                 $i++;
             }
 
@@ -334,9 +341,15 @@ function getShareInfo_json()
 
             foreach ($records as $row)
             {
-                $sharename = User::model()->getName($row['share_uid']); //for conversion of uid to human readable names
+                $iShareUserId = $row['share_uid'];//for conversion of uid to human readable names
+                if ($iShareUserId != 0) { 
+                    $oShared = User::model()->getName($iShareUserId); 
+                    $sSharename = $oShared[0]['full_name'];
+                } else {
+                    $sSharename = 'All users';
+                }
                 $aData->rows[$i]['id'] = $row['participant_id'];
-                $aData['rows'][$i]['cell'] = array($row['firstname'], $row['lastname'], $row['email'], $sharename['full_name'], $row['share_uid'], $row['date_added'], $row['can_edit']);
+                $aData['rows'][$i]['cell'] = array($row['firstname'], $row['lastname'], $row['email'], $sSharename, $row['share_uid'], $row['date_added'], $row['can_edit']);
                 $i++;
             }
 
@@ -1458,6 +1471,12 @@ function shareParticipants()
         $iParticipantId = Yii::app()->request->getPost('participantid');
         $iShareUserId = Yii::app()->request->getPost('shareuser');
         $bCanEdit = Yii::app()->request->getPost('can_edit');
+	
+	    // Some input validation needed
+        if ($iShareUserId == '') {
+            printf($clang->gT("Please select a user"));
+            return;
+        }
 
         $i = 0;
         if (Permission::model()->hasGlobalPermission('participantpanel','update') &&  $iShareUserId>0)
diff --git a/application/models/Participant.php b/application/models/Participant.php
index 9159d3ec7be..ea761f311fe 100644
--- a/application/models/Participant.php
+++ b/application/models/Participant.php
@@ -322,7 +322,7 @@ private function getParticipantsSelectCommand($count = false, $attid, $search =
             // We are not superadmin so we need to limit to our own or shared with us
             $selectValue[] = '{{participant_shares}}.can_edit';
             $joinValue[]   = 'LEFT JOIN {{participant_shares}} ON p.participant_id={{participant_shares}}.participant_id';
-            $aConditions[] = 'p.owner_uid = :userid1 OR {{participant_shares}}.share_uid = :userid2';
+            $aConditions[] = 'p.owner_uid = :userid1 OR {{participant_shares}}.share_uid = :userid2 OR {{participant_shares}}.share_uid = 0';
         }
 
         if ($count) {
@@ -914,7 +914,7 @@ function is_owner($participant_id)
             ->db
             ->createCommand()
             ->select('count(*)')
-            ->where('participant_id = :participant_id AND share_uid = :userid')
+            ->where('participant_id = :participant_id AND ( share_uid = :userid oOR share_uid = 0)')
             ->from('{{participant_shares}}')
             ->bindParam(":participant_id", $participant_id, PDO::PARAM_STR)
             ->bindParam(":userid", $userid, PDO::PARAM_INT)
diff --git a/application/views/admin/participants/displayParticipants_view.php b/application/views/admin/participants/displayParticipants_view.php
index d699060cb1e..d1111028d0f 100644
--- a/application/views/admin/participants/displayParticipants_view.php
+++ b/application/views/admin/participants/displayParticipants_view.php
@@ -254,7 +254,10 @@
 <?php eT("User with whom the participants are to be shared"); ?></p>
     <p>
         <?php
+
         $options[''] = gT("Select...");
+        $options[0]  = gT("All users");
+
         foreach ($names as $row)
         {
             if (!(Yii::app()->session['loginID'] == $row['uid']))