How Delete session by the name

Question

How delete php session by the name example i have session['sec'] and session['page'] i need to delete session['page'] with out delete session['sec']

Answer 1

// for a single variable
unset($_SESSION['session_var']); 

// destroy the Session, not just the data stored!
session_destroy();

// delete the session contents, but keep the session_id and name:
session_unset();