How to live update browser game attributes like the 4 resouces in Travian game?

[taso]

I would like to make a web-based game which is Travian-like (or Ikariam-like). The game will be in PHP & MySQL-based. I wonder how can I achieve the live updating of game attributes. For frontend, I can achieve by using AJAX calls (fetch the latest values from database), or even fake update of values (not communicated with server).For backend, is this done by a PHP cron job (which runs every few seconds)? If so, can anyone provide me some sample codes?by the way, I know it would be a trouble if I use IIS + FastCGI.=== Version Information ===\[quote\] PHP : 5.2.3 IIS : 6.0 with FastCGI OS : Windows Server 2003 Standard R2\[/quote\]