Anyway to block js?

Anyway to block js?

I can use $.ajax to synchronize a js call but not with css, is there any way I can to block the js when loading css?

 I've googled all over the web, the only thing I found is  http://www.neilmix.com/narrativejs/doc/index.html, but that's way too complicated and am not sure I can get that adapt to my application.