PHP ending sessions(different ways) i dont understand

Question

I\'m trying to understand sessions and how some of the functions to end them work. I\'ve gone to different sites/and even here on SO and, well essentially, nothing is workin

Answer 1

You have to start a session in order to end a session. I recommend taking a look at... http://php.about.com/od/advancedphp/ss/php_sessions_3.htm

// you have to open the session to be able to modify or remove it 
session_start(); 

// to change a variable, just overwrite it 
$_SESSION['size']='large'; 

//you can remove a single variable in the session 
unset($_SESSION['shape']); 

// or this would remove all the variables in the session, but not the session itself 
session_unset(); 

// this would destroy the session variables 
session_destroy(); 

Answer 2

You are missing a session_start() at the top of your logout page. It's trying to modify a session that doesn't exist!