Session in cake php

The CakePHP session component provides a way to persist client data between page requests. It acts as a wrapper for the $_SESSION as well as providing convenience methods for several $_SESSION related functions.

Syntex for write session is :
     $this->Session->write('variable','value');

Syntex for check session is set or not (it gives true or false value) :-
     if(isset('$_SESSION'))
    {........}
If there are more then one session running ,then check session according to variable's value :-
     if($_SESSION['variable'] == 'value')   
     {.....}

If you wish to delete some session data, you can use the unset() or the destroy() function.
The unset() function is used to free the specified session variable:
     unset($_SESSION('variable'));

You can also completely destroy the all the running session by calling destroy() function:
     $this->session->destroy();