$page = $_GET['page'];
$s = isset($_GET['s']) ? $_GET['s'] : '';
if (isset($_POST['action']) && isset($_POST['users']) && current_user_can('manage_options')) {
    check_admin_referer('bulk-instructors');
    $action = $_POST['action'];
    foreach ($_POST['users'] as $user_value) {
        if (is_numeric($user_value)) {
            $instructor_id = (int) $user_value;
            $instructor = new Instructor($instructor_id);
            switch (addslashes($action)) {
                case 'delete':
                    $instructor->delete_instructor();
                    $message = __('Selected instructors has been removed successfully.', 'cp');
                    break;
                case 'unassign':
                    $instructor->unassign_from_all_courses();
                    $message = __('Selected instructors has been unassigned from all courses successfully.', 'cp');
                    break;
            }
        }
    }
}
if (isset($_GET['page_num'])) {
    $page_num = (int) $_GET['page_num'];
} else {
    $page_num = 1;
}
if (isset($_GET['s'])) {
    $usersearch = $_GET['s'];
} else {
    $usersearch = '';