[BNM] Flash - change frame rate halfway through a project

[Shaun Morrison]

Hi BNM

Flash noob problem (Last time I touched Flash was two years ago):

We have made a Flash animation at 12fps, now we have decided to make  
it a much smoother 24fps. Obviously this makes our animation run twice  
as fast. I would like it to run at the same speed as before, but this  
time at 24fps. Is there a property/option that allows you to increase  
the amount/percentage of frames between keyframes in a selection? Or  
do I literally have to select between each keyframe and press F5?  
Laborious to say the least.

Basically I want to make my animation twice as long - it should be  
simple right?

Thanks,
Shaun