this code:
<input type="hidden" name="pickup" value="<?php echo isset($_POST[pickup]?$_POST[pickup]:""); ?>" />
is not correct, it should be:
<input type="hidden" name="pickup" value="<?php echo isset($_POST['pickup']?$_POST['pickup']:""); ?>" />
also, make sure that the hidden form element code is inside of the form tag with the rest of the hidden form elements on the confirm page