Best way to go about Instant Messaging?

[MtPHP2]

Hi,
I would like to make an Instant Messaging system for my site users. What would be the best way to go about doing this? I have a Web Mail system (a lot like this forums Private Messaging) but my users are always telling me it is to slow.
Any advice and help much apreciated.
Thanks in advance for any help.

[diego25]

I would do the IM in Java, not in PHP...

Diego

[MtPHP2]

You would? Lovely. I don't know Java. How could I do it in PHP?

[diego25]

You can't, really, coz PHP can't push data to the server (which is what IM needs). PHP can only wait for the browser to pull data from PHP. So one way to do this is to have the browser reload the PHP script every 5 seconds or so and the PHP script will check if there is a new message in the database...

Diego