The IRC chat screen is a way for registered members to communicate in real time. You may have heard of something on TV about live web chats after a programme, this is very similar.
Once you click the 'Chat' link in the top menu, wait for the screen to load (takes a few seconds) and click 'Connect'.
If you wish you can change your nickname, but there is no need to. The screen then takes 30 seconds or more to connect to the chat server. When the connection is established, your name will appear in the right hand panel.
To participate in the chat session, simply click in the bottom entry panel, type your message and press enter.
Your message will be copied to the main panel and everyone who is connected to the server will be able to see it.
Have fun - Hope to see you in chat sometime soon.