Hello, I would like to ask you for help. This days I am trying to build one of my applications. But I have problem which stopped me. I have folder whit php files like connect.php, delete.php etc. These files contains classes named the same as files. So in file connect.php is class Connect. These files are placed in folder named mysql and this folder is inside folder named db. In folder db is a php file named mysql.php, in this file I include classes from folder mysql, after include I declare class MySQL and in it I have method __construct(). In this method I create dynamic objects from included classes. And this is the problem that I can not solve, I have more then one of this files(mysql.php[whit class MySQL], oracle.php[whit class Oracle] etc.) and I need to include them to file called db.php that is in the main folder of my app. In db.php is an class called db, how can I add classes MySQL, Oracle etc. to class db? I try to use abstract class whit __set and __get methods but I also need to include class db to main class application. I am really sorry for my English, so please be indulgent. So I need to connect classes like this: application->db->mysql->connect, but I can not use extends because in php you can have only one parent class. The reason why I am trying to do something like this is because I want to call methods like this: $test = new application(); $test->db->connect(); If it is mysql or othet database I set in config.php file. I need to achieve this schema( -> is something like ../ it means that it is one level up folder): connec.php(class Connect MySql)-> select.php(class Select MySql) -> .... -> mysql.php(class MySQL include all classes, Connect...)-> .... -> ... -> -> db.php(class db include all classes, MySQL, Oracle..) connec.php(class Connect Oracle)-> select.php(class Select Oracle ) -> .... -> oracle .php(class Oracle include all classes, Connect...)-> .... -> ... -> download.php(class Download)-> unzip.php(class Unzip) -> .... -> files.php(class Files include all classes, Download...) -> file.php(class file include class Files) .... -> ... -> hash.php(class Hash)-> capcha.php(class Capcha) -> .... -> secure.php(class Secure include all classes, Hash...) -> security.php(class security include class Secure) .... -> ... -> ect. ect. ect. ect. ect. ect. ect. ect. ect. ect. ect. ect. ect. ect. ect. And in the end, in the same folder as db.php and security.php I will have file application.php which will contain class application and in its __construct() method I will make link classes db, security, file ect. ect. So I will just include file application.php make object from class application and then just do $object->db->connect()(of course if it will by MySql or other database will be stored in some config.php file). Thanks, Dominik