Edit the action script in swf files

I've been trying for 10 hours to edit this swf file. It looks exactly like it's suppose to in the decompiler, but when I export it to flash it's a blank canvas and I have no access to the action script.

All I want to do is edit some stuff in the action script I'm not even touching the movie. Is there an eas开发者_如何学编程ier way to do this?

---

This application is perfect for that, I used it to update a web address for a movie that was created for our company before I worked there and it worked really well.

http://www.free-decompiler.com/flash/