AJAX form submission

i need an ajax form submission script written that will post information to a web form that is hosted on a separate domain. > the information will be pre-compiled from either a flat-file or mysql db. no information will be "gathered" from the user. > the user will click on a link and the information will post to the form and re-direct the user back to a custom landing page after posting. > the process must be hidden from the user and be usable in the major browser programs - FF/IE