Yeah I second that it might well be someone who wants to prove himself, or a geek with poor social skills who want to befriend you by commenting on your work.

Yeah I second that it might well be someone who wants to prove himself, or a geek with poor social skills who want to befriend you by commenting on your work. It is pretty rude to just ask outright of anyone to rewrite their code, a writing such a request as a suggestion or opening to discussion is much friendlier. It would not be rude if there's a critical problem, but just a small performance increase is way out of line. The correct way to deal with this is of course to add the script tags at the bottom of the page ;) (apart from your coworker not noticing - it's better for performance as (most?) browsers completely stop doing anything but loading javascript when they encounter a javascript tag).