The link I gave you is rubbish. The entry for session_start is probably all you need to know. It's a simple way of communicating data across a user's session visiting your page:
PHP Code:
<?php
session_start();
if (!isset($_SESSION['utm_domain'])) { // check for something that would definitely be in session if user had visited before
$qpairs = parse_query($_SERVER['QUERY_STRING']);
foreach ($qpairs as $key => $value) {
$_SESSION[$key] = $value
}
}
function parse_query($var) {
$var = explode('&', html_entity_decode($var));
$arr = array();
foreach($var as $val) {
$x = explode('=', $val);
$arr[$x[0]] = $x[1];
}
return $arr;
}
?>
After this first visit, there will be a bunch of $_SESSION variables, one for each item passed in the query string.
Bookmarks