addChild from within function

programming flash
1

Hi,
I am new to AS3, but in the past I have use the constructor class to draw a circle, using this code:

package {
    import flash.display.*;
    public class snake extends MovieClip {
        public var mc1:MovieClip = new MovieClip();
        public function snake() {
            mc1.graphics.lineStyle(1);
            mc1.graphics.beginFill(0xff0000);
            mc1.graphics.drawCircle(20,20,40);
            this.addChild(mc1);           

        }
}
}

and then in frame in the document class, “snake” ( I am trying to make a basic snake game at the moment, but haven’t got very far) and I found that that would draw the circle using the constructor.

Now I want to know, how would I call that through a non-constructor.I would like to do something like:
var snakeone:snake: = new snake;
snakeone.displaycircle();

in the actions of frame one, but I can’t seem to get that to do anything if I rename he function. What am I doing wrong? DO I need to set the document class as something different?

All help appreciated - I am really new at this.