Implementing jquery Chat

I would like to add a simple chat functionality to my web site. I found this: http://www.cs.开发者_开发知识库illinois.edu/homes/wenpu1/chatbox.html

which basically covers jquery stuff and css. All I need to to is add inserting messages to db etc. The problem is that I need to identify unique visitors/guests. Is there something like Unique Browser Id? so that I know which person to respond to.

I'm thinking of creating Session that would be given a unique GUID for every visitor of the site. is this a good solution? thanks

Yes, a session GUID is a good and very commonly-used idea. Stick it in a cookie.