What is the best way to reuse functions in Flex MVC environment?

I am using a Cairngorm MVC architecture for my current project.

I have several commands which use the same type of function that returns a value. I would like to have this function in one place, and reuse it, rather than duplicate the code in each command. What is the best way to do this?

Create a static class or static method in one of your Cairngorm classes.

class MyStatic
{
    public static function myFunction(value:String):String
    {
        return "Returning " + value;
    }
}

Then where you want to use your function:

import MyStatic;

var str:String = MyStatic.myFunction("test");

Another option is to create a top level function (a la "trace"). Check out this post I wrote here.