Php OOP

// connection database

<?php

    class connectDb{

        private $hostName   = 'localhost';
        private $dbName     = 'php_tut';
        private $dbUser     = 'root';
        private $dbPassword = '';
        private $conn       = false;

        function connect(){

            try{

                $this->conn = new PDO("mysql:host=$this->hostName;dbname=$this->dbName","$this->dbUser","$this->dbPassword");

                return $this->conn;

            }catch(PDOExeception $e){

                return die("error : " . $e->getMessage());
            }

        }

        function disconnect(){
            return $this->conn = NULL;
        }

    }

// class user : function insert user into database

    require_once("connection.php");

    class Users implements userFunctions{

        protected $username;
        protected $password;
        protected $level;
        protected $town;
        protected $country;

        function insertUser($username,$password,$level,$town,$country){

            $this->username = $username;
            $this->password = $password;
            $this->level = $level;
            $this->town = $town;
            $this->country = $country;

            $req = "INSERT INTO users(username,password,level,town,country)
            VALUES(:username,:password,:level,:town,:country)";

            $db = new connectDB();
            $conn = $db->connect();

            $stmt = $conn->prepare($req);

            $stmt->bindValue(":username",$this->username,PDO::PARAM_STR);
            $stmt->bindValue(":password",$this->password,PDO::PARAM_STR);
            $stmt->bindValue(":level",$this->level,PDO::PARAM_STR);
            $stmt->bindValue(":town",$this->town,PDO::PARAM_STR);
            $stmt->bindValue(":country",$this->country,PDO::PARAM_STR);

            $stmt->execute();

            echo "record added";

        }
    }