AJAX Support Chat with visitor tracker and invitation

I really wanted to develop my own support chat with fully AJAX technology, would it be great that if the chat room would not do a single postback to server and get that annoying refresh sound. This Support Chat is a primary feature for me in my http://www.zendsms.com/ project; it’s a Microsoft Outlook 2007 Mobile Service. Therefore here I am with my Support Chat, below are some features that I had prioritized.