Yep, you're right. I already had downloaded that script a while ago and put it in my local server. I tried to delete one of the forms, but it seems that only the JSON one keeps working. I haven't had time to see if I could find something in the documentation, which already seems rather sparse.
Either try to ask with them or see if you find something that works as you wish at, among others,
http://www.ajaxdaddy.com/.