Map Pan and Zoom, Open Source, Almost finished. Please Help

Hey, I´m trying to achieve like a google map app. It has to zoom with mouse wheel and pan with mouse. now, everything works great. the problem is, that the pivot should change dynamicaly where the mouse cursor is, and I don´t know how to do that.

I´ve found the code to make it works, but i am not sure how to blend it with the map.
So here are the files.

What we have so far with the map: www.4render.com/downloads/mapsample.swf
The code to change dynamically the pivot: www.4render.com/downloads/changepivot.swf

Source codes:
www.4render.com/downloads/changepivotpoint.zip
www.4render.com/downloads/mapsample.zip

i´m desparate, please help!. i´ll leave the source code open eternally so everybody can use it!

thanks in advance,

Nat