title: Which is better Comet or AJAX in term of 10->15 second polling?
body: <p>My site almost done but i have a problem. Every 10->15 seconds my site will search the database to check whether there are updates or not. If there are updates then send a notification to user who online.
  I search google and found two solutions: Comet and AJAX. Which is better in my case. or is there a better solution?</p>