[bawolff]

Not sure how this is relavent, but IE had document.execCommand('ClearAuthenticationCache'); for http or TLS auth. Dont think other browsers have anything

[zzo38computer]

Yes, I heard of that, although that is done by the document script and what I was asking is a command for the user to enter instead.

[bawolff]

Http basic/digest auth doesnt last beyond the session, so just close the browser window?

Probably putting a different username in the url would work too (in non ie)