If you've cleared cache on your computer since your last visit, the chatzy site requires that you request your personal password from them so you can re-enter the chatroom once you've left it. To do so, click on the chatzy link, then click on the login link and request your password be emailed to you. It will be sent to the email address where the invitation was sent.
There are two passwords needed to re-enter the room. The first one is your personal password that you received from Chatzy. You enter that when you login to the website. The second password is the room password and that one is able2chat. You enter that one on the screen you navigate to after logging in.
Once done you're in the lobby of the chatroom. Click on the Join Chat button to join the chat.