PHP error when accessing any option - php

Question

I am using phpMYADMIN and netbeans for coding, when pressing run project in netbeans at the top of my page I get this error: `
Warning: include(utils/mysql.class.php): failed to open stream: No such file or directory in C:\xampp1\htdocs\autonuoma\index.php on line 6
Warning: include(): Failed opening 'utils/mysql.class.php' for inclusion (include_path='C:\xampp1\php\PEAR') in C:\xampp1\htdocs\autonuoma\index.php on line 6
My whole is index.php is:
<?php
// nuskaitome konfigūracijų failą
include 'config.php';
// iškviečiame prisijungimo prie duomenų bazės klasę
include 'utils/mysql.class.php';
// nustatome pasirinktą modulį
$module = '';
if(isset($_GET['module'])) {
$module = mysql::escape($_GET['module']);
}
// jeigu pasirinktas elementas (sutartis, automobilis ir kt.), nustatome elemento id
$id = '';
if(isset($_GET['id'])) {
$id = mysql::escape($_GET['id']);
}
// nustatome, kokia funkcija kviečiama
$action = '';
if(isset($_GET['action'])) {
$action = mysql::escape($_GET['action']);
}
// nustatome elementų sąrašo puslapio numerį
$pageId = 1;
if(!empty($_GET['page'])) {
$pageId = mysql::escape($_GET['page']);
}
// nustatome, kurį valdiklį įtraukti šablone main.tpl.php
$actionFile = "";
if(!empty($module) && !empty($action)) {
$actionFile = "controls/{$module}_{$action}.php";
}
// įtraukiame pagrindinį šabloną
include 'templates/main.tpl.php';
?>
When I click some menu option in the webpage it returns an error also:
Warning: include(utils/mysql.class.php): failed to open stream: No such file or directory in C:\xampp1\htdocs\autonuoma\index.php on line 6
Warning: include(): Failed opening 'utils/mysql.class.php' for inclusion (include_path='C:\xampp1\php\PEAR') in C:\xampp1\htdocs\autonuoma\index.php on line 6
Fatal error: Uncaught Error: Class 'mysql' not found in C:\xampp1\htdocs\autonuoma\index.php:11 Stack trace: #0 {main} thrown in C:\xampp1\htdocs\autonuoma\index.php on line 11
My question is, what is causing this? The webpage is loading, but it doesn't let me click anything since mentioned error occurs. I know this might sound very silly but I cannot locate the error
`