Cara mudah konversi dan migrasi PHP 5 ke PHP 7 pada SIASELAH

Assalamualaikum Warahmatullahi Wabarakatuh...
Bagi Anda yang masih kesulitan migrasi PHP 5 ke PHP 7 terutama ketika aplikasi sdh diupload ke hosting, sementara penyedia layanan hosting menggunakan PHP 7 dan aplikasi Anda menggunakana PHP 5 sehingga TROUBLE spt aplikasi SIASELAH.
Caranya:
1. Download file: parser-php-version.php (sdh kami sertakan)
2. Taruh file tersebut di folder utama (public_html)
3. Buka file koneksi.php
4. Lakukan include file:parser-php-version.php  pada file koneksi php seperti berikut:
====================================================================
<?php 
include "parser-php-version.php"; //Konversi dan migrasi PHP version
 
date_default_timezone_set('Asia/Jakarta');
$server = "localhost";
$username = "####";
$password = "####";
$database = "####";
mysql_connect($server,$username,$password);
mysql_select_db($database);
 
function anti_injection($data){
  $filter = mysql_real_escape_string(stripslashes(strip_tags(htmlspecialchars($data,ENT_QUOTES))));
  return $filter;
}
 
function average($arr){
   if (!is_array($arr)) return false;
   return array_sum($arr)/count($arr);
}
 
function cek_session_admin(){
	$level = $_SESSION[level];
	if ($level != 'superuser' AND $level != 'kepala'){
		echo "<script>document.location='index.php';</script>";
	}
}
 
function cek_session_guru(){
	$level = $_SESSION[level];
	if ($level != 'guru' AND $level != 'superuser' AND $level != 'kepala'){
		echo "<script>document.location='index.php';</script>";
	}
}
 
function cek_session_siswa(){
	$level = $_SESSION[level];
	if ($level == ''){
		echo "<script>document.location='index.php';</script>";
	}
}
 
?>