Reusable classe

Hi,

I have been practicing and trying to understand how classes work and I was wondering if it is possible to create a class that can be reused by declearing the class only once in my fla file.

Rightnow I create an instance of the class than I asign it to a MovieClip the problem is that I can only use it once and if I want to use it again I have to create another instance of the same class, something like this.

var sample:Sample = new Sample();
var sample2:Sample = new Sample();
sample.doSomething(mc, some parameters);
sample2.doSomething(mc2, some parameters);

I would like to be able to create an instance of the class and be able to use it as many times as you want without having to create an instance of the class everytime I want to use it with a different MovieClip, something like this.

var sample:Sample = new Sample();

sample.doSomething(mc, some parameters);
sample.doSomething(mc2, some parameters);
sample.doSomething(mc3, some parameters);

Can someone explain how can I create a class that can do this?