Removing/clearing JQuery cookie upon logout

Removing/clearing JQuery cookie upon logout

How can I make certain the "accordion" cookie is completely removed when the user logs out?

Here's where the cookie is set:

   var accordion = $("#accordion");
   var index = $.cookie("accordion");
   var active;
   if (index !== null) {
      active = accordion.find("h3:eq(" + index + ")");
   } else {
      active = 0
   }
   accordion.accordion({
      header: "h3",
      event: "click hoverintent",
      active: active,
      change: function(event, ui) {
         var index = $(this).find("h3").index ( ui.newHeader[0] );
         $.cookie("accordion", index, {
            path: "/"
         });
      },
      autoHeight: false
   });


And here's the existing logout page:

<?php

if ( !defined( 'SMARTY_DIR' ) ) {
   include_once( 'init.php' );
}

$osDB->query( 'DELETE FROM ! WHERE userid = ?', array( ONLINE_USERS_TABLE, $_SESSION['UserId'] ) );

$osDB->disconnect();

session_destroy();

setcookie($config['cookie_prefix']."site_info[username]", $cookie['username'], strtotime("-1day"), "/" );

setcookie($config['cookie_prefix']."site_info[dir]", $cookie['dir'], strtotime("-1day"), "/" );

unset( $_COOKIE[$config['cookie_prefix'].'site_info'] );

unset( $cookie );

unset( $_SESSION );

header('location: index.php');
exit;
?>