Run query_posts if SESSION is empty?

Question

I am having trouble running query_posts when my page loads for the first time, i.e Session is empty.

When the page loads for the first time and the SESSION is empty, the following code runs:

    <?php
    $id = 106;
  if ((empty($_SESSION['r1']))){            
            echo "This Line Prints";
            query_posts("cat=-.'$id'&".$query_string);
            wp_reset_query();
                echo "This Line also Prints";
        }
    ?>

The two statements mentioned in the above code are printing but the query_posts is not running here. However when I am running it outside the session it is working fine :S How can I run this query_posts if the Session is empty? Why doesn't this code work?

Answer 1

if ( empty($_SESSION['r1']) ) {
    global $query_string;         
    query_posts($query_string . "&cat=-" . $id);
}

This should work, depending on $id is set.