carrying a query string

hi all, will urlencode($QUERY_STRING) be sufficient enough conversion of the query string to enable me to pass the query string around as a var in the url? eg current script: page.php?var1=foo&var2=bah <? $script = $_SERVER['PHP_SELF']; $qs = $_SERVER['QUERY_STRING']; $ref = urlencode($script.$qs); <A HREF="email_a_friend.php?ref=$ref">email this page to a friend</a> ?> Then on email_a_friend.php I can urldecode() the $ref, so that I now the file and query string of the referring page. I guess I'm worried that urlencode may not sufficiently obscure the old query string, which may cause confusion on the second script. Any suggestions? This is basically a way of me ensuring I have a referring url, since HTTP_REFERER isn't always set my the browser. Thanks, Justin French