AJAX request, wait for response

[Raz316]

Hi everyone, until now I've been using jquery/ajax calls in the following way. Check the server (hosted in same office) every second, usually the response will be null because no changes have occurred.

Now, I am assuming Gmail doesn't do the same when it updates the inbox link (to show there's a new mail - inbox(1)), but how exactly does it deal with it? Is it something along the lines of the server not responding until a change occurs?

What wording am I looking for so I can do a search for this kind of thing?

Ta

[Raz316]

I think what I am looking for is long polling (or Comet)