diff --git a/main/dropbox/dropbox_download.php b/main/dropbox/dropbox_download.php
index 2ad91e263a..63e8096df5 100644
--- a/main/dropbox/dropbox_download.php
+++ b/main/dropbox/dropbox_download.php
@@ -83,11 +83,7 @@ if (!isset($_GET['id']) || !is_numeric($_GET['id'])) {
 
 // Check if the user is allowed to download the file
 $allowed_to_download = false;
-
-// Check if the user has sent or received the file.
-$sql = "SELECT * FROM ".$dropbox_cnf['tbl_person']." WHERE c_id = $course_id AND file_id='".intval($_GET['id'])."' AND user_id='".api_get_user_id()."'";
-$result = Database::query($sql);
-if (Database::num_rows($result) > 0) {
+if (user_can_download_file($_GET['id'], api_get_user_id())) {
 	$allowed_to_download = true;
 }
 
@@ -109,8 +105,7 @@ if (!$allowed_to_download) {
     if (!Security::check_abs_path($path, dropbox_cnf('sysPath').'/')) {
     	exit;
     }
-	$file = $work->title;
-	require_once api_get_path(LIBRARY_PATH).'document.lib.php';
+	$file = $work->title;	
 	$mimetype = DocumentManager::file_get_mime_type(true);
 	$fileinfo = pathinfo($file);
 	$extension = $fileinfo['extension'];
diff --git a/main/dropbox/dropbox_functions.inc.php b/main/dropbox/dropbox_functions.inc.php
index 84caa30cf9..e90795bd51 100644
--- a/main/dropbox/dropbox_functions.inc.php
+++ b/main/dropbox/dropbox_functions.inc.php
@@ -968,18 +968,9 @@ function format_feedback($feedback) {
 * @version march 2006
 */
 function feedback_form() {
-    $course_id = api_get_course_int_id();
-
-	global $dropbox_cnf;
-
-	$return = get_lang('AddNewFeedback').'<br />';
-
-	// we now check if the other users have not delete this document yet. If this is the case then it is useless to see the
-	// add feedback since the other users will never get to see the feedback.
-	$sql = "SELECT * FROM ".$dropbox_cnf['tbl_person']." WHERE c_id = $course_id AND file_id = ".intval($_GET['id']);
-	$result = Database::query($sql);
-	$number_users_who_see_file = Database::num_rows($result);
-	if ($number_users_who_see_file > 1) {
+	$return = get_lang('AddNewFeedback').'<br />';	
+	$number_users_who_see_file = check_if_file_exist($_GET['id']);
+	if ($number_users_who_see_file) {
 		$token = Security::get_token();
 		$return .= '<textarea name="feedback" style="width: 80%; height: 80px;"></textarea>';
 		$return .= '<input type="hidden" name="sec_token" value="'.$token.'"/>';
@@ -991,6 +982,40 @@ function feedback_form() {
 	return $return;
 }
 
+function user_can_download_file($id, $user_id) {
+    global $dropbox_cnf;
+    $course_id = api_get_course_int_id();
+    $id = intval($id);
+    $user_id = intval($user_id);
+    
+    $sql = "SELECT file_id FROM ".$dropbox_cnf['tbl_person']." WHERE c_id = $course_id AND user_id = $user_id AND file_id = ".$id;    
+	$result = Database::query($sql);
+	$number_users_who_see_file = Database::num_rows($result);
+    
+    $sql = "SELECT file_id FROM ".$dropbox_cnf["tbl_post"]."  WHERE c_id = $course_id AND dest_user_id = $user_id AND file_id = ".$id;
+    $result = Database::query($sql);
+	$count = Database::num_rows($result);    
+    return $number_users_who_see_file > 0 || $count > 0;
+}
+
+// we now check if the other users have not delete this document yet. If this is the case then it is useless to see the
+	// add feedback since the other users will never get to see the feedback.
+function check_if_file_exist($id) {
+    global $dropbox_cnf;
+    $id = intval($id);
+    $course_id = api_get_course_int_id();
+    $sql = "SELECT file_id FROM ".$dropbox_cnf['tbl_person']." WHERE c_id = $course_id AND file_id = ".$id;    
+	$result = Database::query($sql);
+	$number_users_who_see_file = Database::num_rows($result);
+    
+    $sql = "SELECT file_id FROM ".$dropbox_cnf["tbl_post"]."  WHERE c_id = $course_id AND file_id = ".$id;
+    $result = Database::query($sql);
+	$count = Database::num_rows($result);    
+    return $number_users_who_see_file > 0 || $count > 0;
+}
+
+
+
 /**
 * @return a language string (depending on the success or failure.
 *