AS3 move image as the mouse moves

This 开发者_运维问答probably will be very easy for some, but I am stuck on this. I have a map in a movieclip(mc_map) on stage and a small square which acts as a mask to the really bigger size of the same map. What I am want to do is that when I move the mouse on the mc_map(eg: say my cursor is on New York), the small sqaure window will unhide the same area, or will move that bigger image such that the same area is shown under the square mask. I also want to add another cursor(or crosshair) to the stage which is live only in the area of the square and replicates the position of mouse on map. Any help on this will be great thanks.

There are a lot of tutorials on this type of "magnify" effect. See if this one helps: http://www.flashuser.net/flash-actionscript-as3/create-a-magnifying-glass-in-actionscript-3-0.html