how does list get passed thru' sessions

I make the script remembering the values from the previous session by: <a href="index.php?button=back&start=<?php echo("$start"); ?>&end=<?php echo("$end");"></a> My first question is: how do I pass an array using this method? My second question is: without using session provided by PHP, is there any way of doing it without the name and value pair show up on the browser? I know form with hidden variable should do it, but then how is it possible to submit a form without submit button? thanks ---Sonia