Mouse controlled char + scrolling

I’ll use this as an example:
http://www.flashkit.com/movies/Games/RPG_-_en-Itamar_L-7738/index.php

How would I make it so when the character gets to the edge of the screen it scrolls to show more of the map? When using a mouse that is.
http://www.tonypa.pri.ee/tbw/tut14.html is a tutorial for scrolling when the character is controlled by the keyboard but I have no idea how to setup something like that when they are controlled by mouse.

Is it even possible to do in flash? It seems like it would be but I haven’t seen any games that even work like that. Any help is appreciated, this is driving me nuts. XD