AS code eating up a lot of space

I am creating a banner ad, and it needs to be 40K. I have only 4 images in it, and they are highly compressed. When I render it out, my .swf ends up being 50K. I am trying to compress it further, so I generated a size report form Flash to let me know what was taking up space.

It tells me:

ActionScript Bytes Location


         39393    Scene 1:Frame 1

Does this mean the Actionscript alone is taking up nearly 40K?

What can I do to minimize this file further?