$query1 = "SELECT u.email, cu.user_id from $main_course_user_table cu, $main_user_table u where cu.course_code= '$coursecode' and cu.status = '1' and c.user_id=cu.user_id";
$query1 = "SELECT u.email, cu.user_id from $main_course_user_table cu, $main_user_table u where cu.course_code= '$coursecode' and cu.status = '1' and u.user_id=cu.user_id";