mouseX in a class

programming flash
1 

    _xPercent = mouseX / _stage.stageWidth;
    _yPercent = mouseY / _stage.stageHeight;

if I want to use mouseX and mouseY in my class whats the most effective way to do this?
I know if I extend a class to Sprite for example I get this feature but could I get it with less…

I know I could say this also and then I wouldnt need to extend Sprite but I dont know if this is a good idea…


    _xPercent = _stage.mouseX / _stage.stageWidth;
    _yPercent = _stage.mouseY / _stage.stageHeight;