As a matter of security, no browser will EVER "echo" the password back after a postback. This is by design, and you should carefuly consider why this would be a requirement. Almost everybody knows that registration form errors (processed after a postback) as well as login forms, etc., clear the password, so I suggest you're better off educating users instead of bypassing this feature. Let them save their passwords in the browser if they want to, but remember its THEIR responsibility if they do so.
This was first published in August 2003