Revolving script

I see this already used, I want a script that simply makes 1 prim revolve around another prim. Must be adjustable to 50 meters and must have variable revolving speeds. I would preferably want this script to run without any input from any user. I know this is not a difficult script, and most likely available free and free is what I want it for . Could anyone lend a helping hand?

You might find the discussion and examples here some help: /54/92/263006/1.html