objects and $_SESSION access control

hi List, I have written a library of php classes to manage database objects. So my application now access to this library instead of accessing directly to the database. Now, I need to add an access control to my classes, like a check to a $_SESSION variable. A solution can be add this lines in first rows in every method: " session_start();if(!isset($_SESSION['user'])) { return 999; } " ex: class sysAccess{ ..... function getName() { session_start();if(!isset($_SESSION['user'])) { return 999; } .. } } In this way, I am sure that only trusted users have an access to the methods. But, If I forget to "protect" a single method, there will be a serious vulnerability ..and this task will be long (and boring..) Is there a better solution to protect access to publics object's methods only to granted accounts? Thanks in advance Lorenzo Marussi