Form 'post' action = ..../docid?Savedocument WITH AJAX

hi folks,

i did ask earlier how to update notesdocument field´s value with savedocument. nobody answered but i figured out how to.

using

       <input type="hidden" name="<notesFieldname>">

where is the field i want to update in the notes document.

now does somebody have tips on how to do the same thing, but using ajax?

not asking for a solution, just tips! thanks in advance!