Alert new case owner

How can I notify a case owner when a new case is assigned to them OR when the case ownership changes from one user to another (I need to notify the new user. )

I found this post
http://help.zoho.com/portal/en/community?ftid=2266000000008756

But it isn't quite what I need. Perhaps someone has a suggestion that will help me use the information in that post to do what i need?

Thanks