diff --git a/main/inc/ajax/skill.ajax.php b/main/inc/ajax/skill.ajax.php
index 92ce029acf..f0a4f6893d 100755
--- a/main/inc/ajax/skill.ajax.php
+++ b/main/inc/ajax/skill.ajax.php
@@ -298,7 +298,7 @@ switch ($action) {
             $params['skills'] = $params['skill_id'];
             $profileId = isset($_REQUEST['profile']) ? intval($_REQUEST['profile']) : null;
             if ($profileId > 0) {
-                $skill_data = $skill_profile->UpdateProfileInfo($profileId,$params['name'],$params['description']);
+                $skill_data = $skill_profile->updateProfileInfo($profileId,$params['name'],$params['description']);
             } else {
                 $skill_data = $skill_profile->save($params);
             }         
diff --git a/main/inc/lib/link.lib.php b/main/inc/lib/link.lib.php
index fdbf4ea267..1d6c02ae6b 100755
--- a/main/inc/lib/link.lib.php
+++ b/main/inc/lib/link.lib.php
@@ -85,9 +85,11 @@ class Link extends Model
         if (is_null($courseId)) {
             $courseId = api_get_course_int_id();
         }
+        $courseId = intval($courseId);
         if (is_null($sessionId)) {
             $sessionId = api_get_session_id();
         }
+        $sessionId = intval($sessionId);
         if ($linkUrl != '') {
             $query = "UPDATE $tblLink SET url = '$linkUrl' WHERE id = $linkId AND c_id = $courseId AND session_id = $sessionId";
             $resLink = Database::query($query);
@@ -826,7 +828,7 @@ function getLinkCategories($courseId, $sessionId)
 {
     $tblLinkCategory = Database :: get_course_table(TABLE_LINK_CATEGORY);
     $tblItemProperty = Database :: get_course_table(TABLE_ITEM_PROPERTY);
-
+    $courseId = intval($courseId);
     // Condition for the session.
     $sessionCondition = api_get_session_condition($sessionId, true, true);
 
@@ -1116,6 +1118,11 @@ function movecatlink($catlinkid, $courseId = null, $sessionId = null)
     if (is_null($courseId)) {
         $courseId = api_get_course_int_id();
     }
+    $courseId = intval($courseId);
+    if (is_null($sessionId)) {
+        $sessionId = api_get_session_id();
+    }
+    $sessionId = intval($sessionId);
 
     if (!empty ($down)) {
         $thiscatlinkId = intval($down);
diff --git a/main/inc/lib/skill.lib.php b/main/inc/lib/skill.lib.php
index baea453ef1..4fc584f39d 100755
--- a/main/inc/lib/skill.lib.php
+++ b/main/inc/lib/skill.lib.php
@@ -35,8 +35,9 @@ class SkillProfile extends Model
     * @param string $name
     * @param string $description
     */
-    public function UpdateProfileInfo($profileId, $name, $description)
+    public function updateProfileInfo($profileId, $name, $description)
     {
+        $profileId = intval($profileId);
         $sql = "UPDATE $this->table SET name = '$name', description = '$description' WHERE id = $profileId ";
         $result = Database::query($sql);
         return $result;
@@ -77,9 +78,10 @@ class SkillRelProfile extends Model
         $this->tableProfile = Database::get_main_table(TABLE_MAIN_SKILL_PROFILE);
     }
 
-    public function get_skills_by_profile($profile_id)
+    public function get_skills_by_profile($profileId)
     {
-        $skills       = $this->get_all(array('where' => array('profile_id = ? ' => $profile_id)));
+        $profileId = intval($profileId);
+        $skills       = $this->get_all(array('where' => array('profile_id = ? ' => $profileId)));
         $return_array = array();
         if (!empty($skills)) {
             foreach ($skills as $skill_data) {