Register Globals is evil and you should disable it

<?php
if ($name == "Sterling") {
    $loggedin = 1;
}

if ($loggedin) {
    echo "Super Secret Information\n<br />";
}
?>
Use $_FILES, $_GET, $_POST, $_COOKIE, $_REQUEST instead.

<?php
if ($_GET['name'] == "Sterling") {
    $loggedin = 1;
}

if ($loggedin) {
    echo "Super Secret and Somewhat Safe Information\n<br />";
}
?>