Undefined variable: _SESSION in C:\xampp\htdocs\rekam_medis\dokter\prev_antrian.php on line 32

image.png @session_start();

$koneksi= mysqli_connect('localhost','root','','rekam_medis');

$sqllogin = mysqli_query($koneksi,"SELECT * FROM tb_user WHERE pengguna='$_SESSION[user]' AND sandi='$_SESSION[pass]'");

$cek_log = mysqli_fetch_array($sqllogin);

$no=0;

$sql=mysqli_query($koneksi,"SELECT * FROM tb_pendaftaran WHERE stts='1' AND id_dokter='$cek_log[id_dokter]'");

while($bc=mysqli_fetch_array($sql)){

$sql2 = mysqli_query($koneksi,"SELECT * FROM tb_pasien WHERE id_pasien='$bc[id_pasien]'");

$bc2 = mysqli_fetch_array($sql2);

$sql3 = mysqli_query($koneksi,"SELECT * FROM tb_dokter WHERE id_dokter='$bc[id_dokter]'");

$bc3 = mysqli_fetch_array($sql3);