Designing the orbit pattern for a fictional moon

Hi

Odd question, I know, but thats what random forums are for.

I have to animate 3 moons going around a planet in flash.
Thats fine, I can do that.

But the orbits have to accurate to a certain degree.

For example, our moon takes 27 or so days to go around the earth.
So we see a new moon once a month, and lunar phases in between.

Well, these 3 moons each have a new moon cycle once every 12 days.
Only one moon should be visible at a time(although, thats just highly preferred, if its impossible, then I have permission to change it, but only if its truly impossible. Although I don’t see why not, if the moons are small enough, and spaced out evenly around the planet…)

Thats all the information/restrictions I have.
So as far as moon size, distance from the planet etc…
As long as each moon shows up in its own 12 day cycle goes through its phases, goes away, and then other moons show up for their cycle etc…

I’m supposed to give a visual demonstration of what it would look like, using Flash. But the information I can get on the orbit of moons etc… isn’t enough for me to map out the orbits required for these fictional moons.

Haven’t decided on a Frame rate yet, don’t think any particular rate will be required. Probably choose 20 frames.
I think 1 second = 1 day for the animation will suffice. So the moons have their own 12 second loop.

I’d appreciate answers, links, suggestions etc…
Go ahead and make a crack too, as long as this post doesn’t end up full of jokes and no help.

Thanks

-Lem