HTTP, as a stateless protocol, does not support variables that persist across multiple sessions. There are several ways around this limitation:
-- Pass the values explicitly in any links (GET) or form submissions (GET or POST hidden variables).
-- Store the variables in a cookie. See the manual page on set_cookie().
-- Use PHP4 sessions. See the manual. There also are tutorials on sessions here and at zend.com.
-- Use phplib sessions. See the phplib documentation.