How does Comet work? How to write comet chat application person to person

As the title says, i'm working on webchat application where i expect to have lots of users active, and using ajax polling is not an option. I want basicly to make 开发者_JS百科a person 2 person chat, but forgive me please for beeing a noob but i'm really lost. I've read a lot about comet, but i find it all confuzing. How can i make it work the way i want? That's person to person chat.

Hope you'll be able to help me :)

Comet is described at - http://en.wikipedia.org/wiki/Comet_(programming)) - and some Google searches will yield some tutorials. But why would you want to stay away from polling, especially as the Comet approach is still confusing to you?

Polling will work fine for regular sites, scalability will probably only become a problem once your application reaches high amounts of traffic.

Forgive me for any misunderstandings, your question did not have these details.