$HTTP_REFERER

[Anon]

session_register('state');
session_register('theurl');

if (ereg ("$PHP_SELF","$theurl"))
{ $theurlx=$HTTP_REFERER;}
else { $theurl=$HTTP_REFERER;}

if (IsSet($theurl)) {
echo "<a href=\"$theurl\">Back to Browse </a>";
}
else {
echo "<a href=\"show.php"\Back to Browse </a>";
}

When the same page reload the $theurl changes why?

[[deleted]]

There's a quotation error here:
echo "<a href=\"show.php"\Back to Browse </a>";

Are you sure you start the session properly?