You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')' at line 9

Invalid SQL:

        SELECT post.postid, post.title, post.pagetext, post.dateline, post.userid, post.visible AS postvisible,
            IF(user.username, user.username, post.username) AS username,
            thread.threadid, thread.title AS threadtitle, thread.postuserid, thread.visible AS threadvisible,
            forum.forumid, forum.password
        FROM post AS post
        LEFT JOIN user AS user ON (post.userid = user.userid)
        INNER JOIN thread AS thread ON (post.threadid = thread.threadid)
        INNER JOIN forum AS forum ON (thread.forumid = forum.forumid)
        WHERE post.postid IN ();

MySQL Error  : You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')' at line 9
Error Number : 1064
Date         :
Script       : http://www.mysite.com/newreply.php?do=newreply&noquote=1&p=756
Referrer     : http://www.mysite.com/showthread.php?p=756
IP Address   : 
Username     : Admin
Classname    : vb_database