How to merge animation layers in PS?

I'm using the animation function within PS CS3 Extended for the first time. I've imported some video and have done some hand-drawn animation over it using several different layers. So now I've got several different layers of hand drawn animation just stacked on top of my video layer and I want to merge the hand drawn frames into one video layer. But I don't seem to see an obvious way to do that.

Anyone know how?

"If at first you don't succeed, destroy all evidence that you tried in the first place."

Thanks for the response, Mike. However...

Merging layers like one would do normally, does not work in the animation palette for some reason. The animation layers (I guess they're called video "layers") will merge alright, but all the frames in the layer will only be the frame you merged on.

So for example, let's say you had an animation of a bouncing ball over 30 frames that you had done on multiple layers, for whatever reason. If you had your timeline marker parked on the frame where it is up in the air and you proceeded to merge all the layers, then your merged layer will only show the ball up in the air across all frames of your animation.

There should be a way to merge all your animated frames down into one layer for easy editing of your animation. But I can't seem to find one.

"If at first you don't succeed, destroy all evidence that you tried in the first place."

I was googling for just your question, but have now found the answer by myself. You can just select the two (or more) video layers you want to merge and then choose "convert to smart object"

Cheers,
Jonathan