the_posts hook problem

I can’t get this plugin working. The main object of this plugin is to block guests from viewing any post in a set category via plugin file. I’ve set category number as 1. This is my first plugin, so don’t yell at me!

<?php
/*
Plugin Comments removed for posting on www.remarpro.com
*/

$my_cat = “1”;

function applysubbyposts($the_posts) {
global $wpdb;
if(!is_user_logged_in()) {
foreach($the_posts as $key => $post) {
$thiscat = $wpdb->get_var(“SELECT category_id FROM post2cat WHERE post_id=’$post->ID'”);
if(floatval($thiscat) == floatval($my_cat)) unset($the_posts[$key]);
}
}
return $the_posts;
}
add_filter(“the_posts”, “applysubbyposts”);
?>