class controller
{
	...
	protected $mysql_db;
	 
	function __construct()
	{
		$this->mysql_db=new mysql(DB_PATH,DB_NAME,DB_PASS,DATABASE);
		$this->mysql_db->connect_mysql ();
		$this->templ=new template(PATH_TEMPLET_1);
	}
	
        ...
}
class adminControl extends controller
{

	private $templAdd;
		
	function __construct()
	{
		$this->templAdd = new template(PATH_TEMPLET_ADMIN);
	}
        
        function templStart()
	{
	
		$replacement = $this->mysql_db->selectAdmin("SELECT id,title
                    FROM books");
		$this->templAdd-> set_tpl_var("SELECT1", $replacement);
		...
	}
}
На строке вызова метода "selectAdmin" обьекта "mysql_db" выбивается ошибка:
Fatal error: Call to a member function selectAdmin() on a non-object in /var/www/classes/adminControl.php on line 21

function __construct()
{
    parent::__constuct();
    $this->templAdd = new template(PATH_TEMPLET_ADMIN);
}