[rules-users] determining what field changed

Is it possible to determine what fields from an object changed within a rule. So I am using this to determine if any DataObject has changed: //IDENTIFY ANY DATAOBJECT CHANGES rule "identify any DATAOBJECT" when $do : DataObject(); then System.err.println("ANY DataObject change detected:" + $do); End However this also fires when any new DataObject() is injected into the system and the rules are fired. I would like to be able to only have a rule fire when an object is first created Vs. when it is modified and is there a way to detect what values of an object have changed if I don't explicitly know what fields of DataObject changed ahead of time? Thanks, Chris