We are a group of beginners flash developers, and we are making a first game, but we are working in a part each one. So we need to know how we can join the differents files .fla that we are making in only one file .fla ¿is it possible? Please if somebody can help us we are very grateful. And if it is possible as soon as you can, better!
To the best of my knowledge you cannot merge .fla files. You can however use external libraries in a .fla from another .fla and simply copy paste from one stage/library/timeline to the other.
I don't know of an automated way to do this but you could simply select all the layers from each file in turn and copy (ctrl-alt-C) and paste (ctrl-alt-V) them into a new file. To be safe it would probably be a good idea to create a new scene for each pasted timeline. Then you'd just have to copy all your exported movie clips if any of them don't appear on the timeline (highlight them in the library then ctrl-C to copy) from each file into the new one (click in the library, ctrl-V to paste), and that should be everything.