Instant Alert notification feature using PHP

Need to display incoming mails when the u开发者_StackOverflow中文版ser is currently logged in. Can we use socket server programming concept for this requirement. Need help?

http://code.google.com/p/phpwebsocket/

Avoid using PHP's native socket support. They're an absolute mess, you will end up tearing your eyeballs out.

Or you could just poll an ajax script every couple of seconds.