If you just made a change to the HTML code and the chat no longer works, something is not configured properly. Please check over your HTML and make sure it is all correct.
If you have not made any changes recently, the chat server may be down. If the HTTP and FTP servers are working, please wait a few minutes to see if we are rebooting the chat server. If the chat server is still down, please contact us and make sure to include what server you are located on (usually either Thebe or Jupiter).