With Auto Save Plugin, you will never lose your animation again.

Open the Plugin by clicking Window/Other Panels/[T] Auto Save.
Press the button "Disabled".
It will turn Auto Save enabled.
Select the time interval to save.
If the option "New Version" is enabled, it will increase "_vX" to your file.
Ex.: If your file is "My_animation.fla", it will save as "My_animation_v1.fla", "My_animation_v2.fla" and so on.
The button "Save Now" will save the file immediately.

Important: You must leave the plugin window open. If you wish you can minimize it, but if you close it will cancel the auto save process.