Drawing a box with Actionscript

programming flash
1

Hello All,

I have seen some tutorials for this type of thing but not exactly what I was looking for. For instance this code here:

this.createEmptyMovieClip("rectangle_mc", 10);
rectangle_mc._x = 100;
rectangle_mc._y = 100;
drawRectangle(rectangle_mc, 240, 180, 0x99FF00, 100);
function drawRectangle(target_mc:MovieClip, boxWidth:Number, boxHeight:Number, fillColor:Number, fillAlpha:Number):Void {
    with (target_mc) {
        beginFill(fillColor, fillAlpha);
        moveTo(0, 0);
        lineTo(boxWidth, 0);
        lineTo(boxWidth, boxHeight);
        lineTo(0, boxHeight);
        lineTo(0, 0);
        endFill();
    }
}

It draws a box with a green fill but it just shows up. I would like to make it look like it is being drawn. Is there a way to do that with ActionScript or do I have to use masks and tweens?

Thanks in advance for your help.