How hard Is This To Do...

Okay, so I’m really new to this, but here’s what I’d like to be able to do.

I’ve done this

http://www.digi.com/wiki/developer/index.php/XBee_Digital_I/O_Adapter_Relay_Demo#Requirements

But instead of the buttons being used to activate the DIO, I’d like to have a button on a webpage to send the commands to the DIO. Is this possible? And how tough is it?