I think if you understand AS3 this older code is still perfectly readable. Maybe the problem is you don't understand either Let me suggest

http://help.adobe.com/en_US/FlashPla...ctionscript/2/
http://help.adobe.com/en_US/FlashPla...ctionscript/3/

In particular

http://help.adobe.com/en_US/FlashPla...ouseEvent.html
http://help.adobe.com/en_US/FlashPla...redObject.html