{ public function select() { echo 'The class "', __METHOD__, '" was initiated!<br />'; } } class Mssql extends Database { public function connect() { echo 'The class "', __METHOD__, '" was initiated! User : '******' Pass : '******'<br />'; } public function select() { echo 'The class "', __METHOD__, '" was initiated!<br />'; } } $db = new Mysql(); $db->authentication('root', 'root'); $db->connect(); $db->select(); echo "<hr>"; $db = new Postgresql(); $db->authentication('root', 'root'); $db->connect(); $db->select(); echo "<hr>"; $db = new Mssql(); $db->authentication('ali', 'root'); $db->connect(); $db->select();