Fatal error: uncaught error: call to undefined function mysql_real_escape_string()

<?php
include "configurasi/koneksi.php";
function anti_injection($data){
  $functionlter = mysqli_real_escape_string(stripslashes(strip_tags(htmlspecialchars($data,ENT_QUOTES))));
  return $filter;
}

$username = anti_injection($_POST['username']);
$pass     = anti_injection(md5($_POST['password']));

// pastikan username dan password adalah berupa huruf atau angka.
if (!ctype_alnum($username) OR !ctype_alnum($pass)){
  echo "Access not allowed";
}
else{
$login=mysqli_query("SELECT * FROM siswa WHERE username_login='$username' AND password_login='$pass' AND blokir='N'");
$ketemu=mysqli_num_rows($login);
$r=mysqli_fetch_array($login);

// Apabila username dan password ditemukan
if ($ketemu > 0){
  session_start();
  include "timeout.php";

  $_SESSION[namauser]     = $r[username_login];
  $_SESSION[namalengkap]  = $r[nama_lengkap];
  $_SESSION[passuser]     = $r[password_login];
  $_SESSION[leveluser]    = $r[level];
  $_SESSION[idsiswa]      = $r[id_siswa];

  // session timeout
  $_SESSION[login] = 1;
  timer();

	$sid_lama = session_id();

	session_regenerate_id();

	$sid_baru = session_id();

  mysqli_query("UPDATE siswa SET id_session='$sid_baru' WHERE username_login='$username'");

  $user = mysqli_query("SELECT * FROM online WHERE id_siswa='$_SESSION[idsiswa]'");
  if (mysqli_num_rows($user)== 0){
              $ip      = $_SERVER['REMOTE_ADDR']; // Mendapatkan IP komputer user
              $tanggal = date("Ymd"); // Mendapatkan tanggal sekarang
              $waktu   = time("U"); //
      mysqli_query("INSERT INTO online (ip,id_siswa,tanggal,online)
                               VALUES ('$ip','$_SESSION[idsiswa]','$tanggal','Y')");
  }
  else{
     $ip      = $_SERVER['REMOTE_ADDR']; // Mendapatkan IP komputer user
     $tanggal = date("Ymd"); // Mendapatkan tanggal sekarang
     $waktu   = time("U"); //
     mysqli_query("UPDATE online SET ip='$ip',tanggal='$tanggal',online='Y' WHERE id_siswa = '$_SESSION[idsiswa]'");
  }
  header('location:home');
}
else{
  echo "<script>window.alert('LOGIN GAGAL! Username atau Password tidak benar. Atau account anda sedang di blokir!');
            window.location=(href='index.php')</script>";
}
}
?>

Fatal error: Uncaught Error: Call to undefined function mysql_real_escape_string() in C:\xampp\htdocs\cobak\administrator\cek_login.php:4 Stack trace: #0 C:\xampp\htdocs\cobak\administrator\cek_login.php(8): anti_injection('admin') #1 {main} thrown in C:\xampp\htdocs\cobak\administrator\cek_login.php on line 4

<?php include "configurasi/koneksi.php"; function anti_injection($data){ $functionlter = mysqli_real_escape_string(stripslashes(strip_tags(htmlspecialchars($data,ENT_QUOTES)))); return $filter; }

$username = anti_injection($_POST['username']); $pass = anti_injection(md5($_POST['password']));

// pastikan username dan password adalah berupa huruf atau angka. if (!ctype_alnum($username) OR !ctype_alnum($pass)){ echo "Access not allowed"; } else{ $login=mysqli_query("SELECT * FROM siswa WHERE username_login='$username' AND password_login='$pass' AND blokir='N'"); $ketemu=mysqli_num_rows($login); $r=mysqli_fetch_array($login);

// Apabila username dan password ditemukan if ($ketemu > 0){ session_start(); include "timeout.php";

$_SESSION[namauser] = $r[username_login]; $_SESSION[namalengkap] = $r[nama_lengkap]; $_SESSION[passuser] = $r[password_login]; $_SESSION[leveluser] = $r[level]; $_SESSION[idsiswa] = $r[id_siswa];

// session timeout $_SESSION[login] = 1; timer();

$sid_lama = session_id();

session_regenerate_id();

$sid_baru = session_id();

mysqli_query("UPDATE siswa SET id_session='$sid_baru' WHERE username_login='$username'");

$user = mysqli_query("SELECT * FROM online WHERE id_siswa='$_SESSION[idsiswa]'"); if (mysqli_num_rows($user)== 0){ $ip = $_SERVER['REMOTE_ADDR']; // Mendapatkan IP komputer user $tanggal = date("Ymd"); // Mendapatkan tanggal sekarang $waktu = time("U"); // mysqli_query("INSERT INTO online (ip,id_siswa,tanggal,online) VALUES ('$ip','$_SESSION[idsiswa]','$tanggal','Y')"); } else{ $ip = $_SERVER['REMOTE_ADDR']; // Mendapatkan IP komputer user $tanggal = date("Ymd"); // Mendapatkan tanggal sekarang $waktu = time("U"); // mysqli_query("UPDATE online SET ip='$ip',tanggal='$tanggal',online='Y' WHERE id_siswa = '$_SESSION[idsiswa]'"); } header('location:home'); } else{ echo "<script>window.alert('LOGIN GAGAL! Username atau Password tidak benar. Atau account anda sedang di blokir!'); window.location=(href='index.php')</script>"; } } ?>