Using TAB to change focus - is there a better way than this..

Using TAB to change focus - is there a better way than this..

One thing that irks me is lazy/un-optimised scripting which slows down my browser. The jQuery API home page is an example of this! Go to http://api.jquery.com Press the TAB key and notice that the "focus box" moves from one function to the next. But why is it so incredibly slow?

I'm working on a similar sort of page at the moment, and I'd like to know if there's a better - quicker - way of doing this than the API page exhibits, or if I should forget trying to do it. I'd rather present my data a different way than have it turn out that slow.. is there a better way than was done on the api page?