Variables inside class

programming flash
1

hi,
i am creating my own component. the problem is how can i access the variables inside the Class without using _root.myComponentName.variableName.
check out the code.

class Loader extends MovieClip {
private var __maskHeight:Number = 450;

    Loader(){
             //create some movieClip here
             movieClip.onLoad = function():Void{
                 //how can i access the __maskHeight variable here
                 //when i trace it, it shows me undefined
             }
    }

}

Faraz