I use lynx to check a web page for seo friendly links. I think to "view source" to check for links that the browser would have to have javascript disabled.
I read somewhere that Google is reading javascript looking for underhandedness but had not heard that javascript links were good for seo or site navigation.
I use <noscript> for css / drop down menu's to insert links for non-javascript enabled browsers and spiders.
I have seen in other forums that ,Google not follow links in javascript drop down . for other I have no idea and big seo guys told it not good seo to put javascripts for liking in your site navigation.