Flash CS6.
document.saveAsCopy(URI [, selectionOnly])
URI String: The URI to export the new FLA file to. This URI must reference a local file. Example: file:///c|/tests/myTest.fla. selectionOnly Optional. A boolean indicating whether only the current Stage selection should be saved to the new FLA file.
Boolean.
Method; Saves a new FLA file based on the existing document object, with an option to save only the current selection on Stage.
The following example exports the current selection to a new FLA file at the URI specified by the user:
var uri = fl.browseForFileURL("save");
var selectionOnly = true;
fl.getDocumentDOM().saveAsCopy(uri, selectionOnly);