Hi.
In SFS1x there are Rooms, which can represent several things, such as games, map areas, etc. So you will need to have Rooms for each of those "map areas". Then, to switch between these areas, you just have to join the specified room and leave the previous one.
That's the server-side part. On the client-side, you have to show the correct graphics for that Room, based on, for example, the room's name or a Room Variable which says to which map does it refer. For example, if you call a room Beach_1, you can filter that name and then check that it belongs to the Beach area, so you just have to load the according map.
It's advisable for you to load these maps as external swfs, as this way you don't need to have all the maps in the Main swf, saving lots of space and improving performance.
Again, I suggest you to read the docs at
http://www.smartfoxserver.com/docs