To use the chat room you need to have java enabled in your browser. If you have problems enabling Java in your browser get help on this website
If you have followed the guidelines set in other help files then you should be able to enter chat.
If not then the following may have occured:
irc.webchat.org is down- if the server is down then no one will join the chat this way
If you are suffering problems with java chat (the chat off the main page) try downloading mIRC which is much quicker and safer.