Notice: Undefined variable: user_id in D:\xampp\htdocs\E-learning\models\teacher\check_course.php on line 3

Notice: Undefined variable: conn in D:\xampp\htdocs\E-learning\models\teacher\check_course.php on line 7

Fatal error: Uncaught Error: Call to a member function prepare() on null in D:\xampp\htdocs\E-learning\models\teacher\check_course.php:7 Stack trace: #0 {main} thrown in D:\xampp\htdocs\E-learning\models\teacher\check_course.php on line 7