$s_sql_connection_time="SELECT login_course_date, logout_course_date FROM $tbl_track_lcourse_access WHERE user_id ='".$_GET['student']."' AND logout_course_date <> 'null' AND course_code='".$a_cours['code']."'";
$sql_select_courses="SELECT course_rel_user.course_code FROM $tbl_course_user as course_rel_user LEFT OUTER JOIN $tbl_session_course as src ON course_rel_user.course_code=src.course_code WHERE user_id='$i_teacher_id' AND status='1' AND src.course_code IS NULL";
//$sql_select_courses="SELECT course_rel_user.course_code, src.course_code as test FROM $tbl_course_user as course_rel_user LEFT OUTER JOIN $tbl_session_course as src ON course_rel_user.course_code=src.course_code WHERE user_id='$i_teacher_id' AND status='1' AND src.course_code IS NULL";
$sql_select_courses="SELECT course_rel_user.course_code FROM $tbl_course_user as course_rel_user WHERE user_id='$i_teacher_id' AND status='1'";
$sqlStudents = "SELECT user.user_id,lastname,firstname,email FROM $tbl_course_user as course_rel_user, $tbl_user as user WHERE course_rel_user.user_id=user.user_id AND course_rel_user.status='5' AND course_rel_user.course_code='$s_course_code'";