diff --git a/main/gradebook/index.php b/main/gradebook/index.php
index a99ff8b4a9..6b76bf1afa 100755
--- a/main/gradebook/index.php
+++ b/main/gradebook/index.php
@@ -719,9 +719,11 @@ if (isset($_GET['cidReq']) && $_GET['cidReq']!='') {
 } else {
 	$addparams['cidReq']='';
 }
+
 $no_qualification = false;
 
-//here we are in a sub category
+// Show certificate link.
+
 if ($category != '0') {
 	$cat = new Category();
 	$category_id   = intval($_GET['selectcat']);
@@ -729,13 +731,13 @@ if ($category != '0') {
 	$show_message  = $cat->show_message_resource_delete($course_id);
 
 	if ($show_message == '') {
-		//student
+		// Student
 		if (!api_is_allowed_to_edit()) {
             $certificate_html = Category::register_user_certificate($category_id, $stud_id);
             if ($certificate_html) {
                 echo $certificate_html;
             }
-		} //end hack
+		}
 	}
 }
 
@@ -743,7 +745,7 @@ if (api_is_allowed_to_edit(null, true)) {
 	// Tool introduction
 	Display::display_introduction_section(TOOL_GRADEBOOK, array('ToolbarSet' => 'AssessmentsIntroduction'));
 
-	if ( (isset ($_GET['selectcat']) && $_GET['selectcat']<>0) ) {
+	if ( (isset ($_GET['selectcat']) && $_GET['selectcat']<>0)) {
 	//
 	} else {
         if (((isset ($_GET['selectcat']) && $_GET['selectcat']==0) || ((isset($_GET['cidReq']) && $_GET['cidReq']!==''))) || isset($_GET['isStudentView']) && $_GET['isStudentView']=='false') {
diff --git a/main/gradebook/lib/gradebook_functions.inc.php b/main/gradebook/lib/gradebook_functions.inc.php
index e4a6ae4362..3237cb41f2 100755
--- a/main/gradebook/lib/gradebook_functions.inc.php
+++ b/main/gradebook/lib/gradebook_functions.inc.php
@@ -530,7 +530,8 @@ function parse_xml_data($file) {
  * @param Datetime The date when you obtained the certificate
  * @return void()
  */
-function register_user_info_about_certificate($cat_id, $user_id, $score_certificate, $date_certificate) {
+function register_user_info_about_certificate($cat_id, $user_id, $score_certificate, $date_certificate)
+{
     $table_certificate = Database::get_main_table(TABLE_MAIN_GRADEBOOK_CERTIFICATE);
     $sql_exist = 'SELECT COUNT(*) as count FROM ' . $table_certificate . ' gc
     			WHERE gc.cat_id="' . intval($cat_id) . '" AND user_id="' . intval($user_id) . '" ';
@@ -539,7 +540,7 @@ function register_user_info_about_certificate($cat_id, $user_id, $score_certific
     if ($row['count'] == 0) {
         $sql = 'INSERT INTO ' . $table_certificate . ' (cat_id,user_id,score_certificate,created_at)
     		  VALUES("' . intval($cat_id) . '","' . intval($user_id) . '","' . Database::escape_string($score_certificate) . '","' . Database::escape_string($date_certificate) . '")';
-        $rs = Database::query($sql);
+        Database::query($sql);
     }
 }
 
@@ -549,11 +550,13 @@ function register_user_info_about_certificate($cat_id, $user_id, $score_certific
  * @param int The user id
  * @return Datetime The date when you obtained the certificate
  */
-function get_certificate_by_user_id($cat_id, $user_id) {
+function get_certificate_by_user_id($cat_id, $user_id)
+{
     $table_certificate = Database::get_main_table(TABLE_MAIN_GRADEBOOK_CERTIFICATE);
-    $sql_get_date = 'SELECT * FROM ' . $table_certificate . ' WHERE cat_id="' . intval($cat_id) . '" AND user_id="' . intval($user_id) . '"';
-    $rs_get_date = Database::query($sql_get_date);
-    $row = Database::fetch_array($rs_get_date, 'ASSOC');
+    $sql = 'SELECT * FROM ' . $table_certificate . '
+            WHERE cat_id="' . intval($cat_id) . '" AND user_id="' . intval($user_id) . '"';
+    $result = Database::query($sql);
+    $row = Database::fetch_array($result, 'ASSOC');
     return $row;
 }
 
diff --git a/main/inc/lib/certificate.lib.php b/main/inc/lib/certificate.lib.php
index f5f3a827e1..888cde1cbd 100755
--- a/main/inc/lib/certificate.lib.php
+++ b/main/inc/lib/certificate.lib.php
@@ -2,6 +2,7 @@
 /* For licensing terms, see /license.txt */
 
 /**
+ * Certificate Class
  * The certificates class is used to generate certificates from inside the
  * gradebook tool.
  * @package chamilo.library.certificates
@@ -242,7 +243,10 @@ class Certificate extends Model
         if (empty($this->certification_user_path)) {
             return false;
         }
-        if (!empty($this->certificate_data) && isset($this->certificate_data['path_certificate']) && !empty($this->certificate_data['path_certificate'])) {
+        if (!empty($this->certificate_data) &&
+            isset($this->certificate_data['path_certificate']) &&
+            !empty($this->certificate_data['path_certificate'])
+        ) {
             return true;
         }
         return false;