Can you make an estimate of a percentage? Javascript is enabled by default
in IE and Mozilla (and probably others as well) and "many people" would have
no idea of its existance, let alone know how to disable it.
Unfortunately, no one knows. Most estimates range around 10-20%ish. But
the fact that it _can_ be disabled means it can't be relied on.
I've seen a "back to previous page" link on zillions of pages and AFAIK they
all use Javascript.
As if the browser didn't already have a back button. Just because there
are millions of clueless deezyners out there doesn't mean you have to
copy them.
I agree that frames are evil, but Javascript?
Javascript isn't evil. It can be used for optional enhancements to the
site but, as I said, it can't be relied on. Anyone using a text browser,
speech browser, mobile phone/PDA (I think) doesn't even have the option
of Javascript - it simply isn't available. Plus many companies disable
Javascript (or block it) for security reasons.