That page has the saving of the login data for that domain turned off - form method="post" autocomplete="off" action="signin.aspx" in that page's source code - Firefox follows tags like that and doesn't offer to save that data.

This bookmark will override the autocomplete="off" temporarily, allowing you to save passwords even on sites that use autocomplete="off". Remember Password bookmarklet: https://www.squarefree.com/bookmarklets/forms.html#remember_password

I'm not sure if Firefox can handle a three field login routine that deviates from the standard Password / Username - I haven't encountered any myself and I can't any documentation from Mozilla about a 3-field login.

That web site uses autocomplete=off and that prevents Firefox from saving the name and the password.

If a site uses autocomplete="off" then look at this article for a bookmarklet to remove that autocomplete attribute. http://kb.mozillazine.org/User_name_and_password_not_remembered (bookmarklet) http://kb.mozillazine.org/Password_Manager

See also http://en.wikipedia.org/wiki/Bookmarklet --- As there are two text fields in that form you may also need a form fill extension to save the Practice ID field.

Autofill Forms: https://addons.mozilla.org/firefox/addon/4775 SecureLogin: https://addons.mozilla.org/firefox/addon/4429