Language pages for index

Hi,

According the HTML specification
(http://www.w3.org/TR/html401/types.html#type-links), if I add the following
to my index.htm page (served by an ISP I don't have control over):

<link rel="alternate" lang="fr" href="index_fr.htm" hreflang="fr"/>

Shouldn't then the default page be automatically redirected to index_fr.htm
if I don't specify a page and if my browser has its preference settings
listing FR as its first choice?

It doesn't seem to work on IE 6 or NN 7. (Pages have their language-content
set properly, and the lang attribute also set).

- I am mis-interpreting the specification?
- Is it necessary to set something on the server-side as well?
- Are the browsers simply not support it?

In other words: how to get the browser to pick the right language default
page when you don't control the server?

Thanks
-yves