Stumped.. Invalid use of group function (MySQL)

[pureDesi]

I have this query being passed to MySQL:
[code]
UPDATE
forums, threads
SET
forums.lastThreadID=MAX(threads.threadID)-1,
forums.lastMemberID='5',
forums.numPosts = forums.numPosts+1,
threads.replies = threads.replies+1
WHERE
forums.forumID = threads.forumID
AND
threads.threadID = '3'";
[/code]

And I keep getting
[code]#1111 - Invalid use of group function [/code]

I have no clue why and I've tried a couple of different things, but to no avail. Any help would be appreciated.

[artacus]

Easy, you can't use MAX() because you haven't grouped anything to have a max, min, avg etc.

You probably need to use a subquery here.

[pureDesi]

Ahh.. thank you, I've been looking at this page for about an hour refreshing it every 2 minutes until I saw your reply, Thanks :D