Hi,
Having read your requirement, I understand you a chat script to integrate into your site.
I have a chat script built on PHP / JavaScript / MYSQL requiring HTML 5 to work. Most browsers support HTML 5 which the new standard for HTML
The search integrates into a user contacts and list all the user contacts that are online with the option to invite any to chat.
You can review the chat at www.dorcasmall.com.
You have to register to use the feature
Look forward to working for you
Charles