please don't cross-post. in fact, ignore your duplicate message in the as1/as2 forum.
Sorry about the cross post. I thought I only selected Action Script 3. This is my first post and I am new to Flash.
The issue is that I cannot determine how or where to put externalinterface class. I have clicked around, but not found where to put the code such that it attaches itself to the last frame of any tween. I clicked on Commands and tried Run Command..., but I'm not sure if putting the command in a file and then clicking OK will do it.
I looked at the Actions dialog, but it says my current selection cannot have actions applied to it.
you don't put the class anywhere. you just use its methods. i don't think you even need to import it when using as3:
ExternalInterface.call("yourJSfunction", "any variable(s) you want to send");
Sounds great. Where do you type it such that it executes on the last frame of a Motion Tween?
create a keyframe at the end of your tween (using a different layer) and, place the code there.