Creating Accessible JavaScript
http://www.webaim.org/techniques/javascript/

WebAIM
2003

Abstract:

JavaScript is available on the Web to allow programming type processes that are not allowed with static HTML. In most cases, JavaScript does not overtly affect accessibility. Most browsers and screen readers are capable of accessing JavaScript items. You should, however, teach that many people cannot or choose not to allow JavaScript within their Web browsers or assistive technologies. Important content or functionality should not rely on JavaScript alone. JavaScript should usually be used to supplement content.