Constants as Function Argument Defaults

const RADIUS = 10;
const COLOR = 0xCCCCCC;

function createCircle(xp:Number, yp:Number, radius:Number = RADIUS, col:uint = COLOR):void{
	var c:Sprite = new Sprite();
	c.graphics.beginFill(col);
	c.graphics.drawCircle(xp, yp, radius);
	addChild(c);
}

// optional last 2 values are populated with const defaults
createCircle(100,100);
// optional color value is populated with default 0xCCCCCC;
createCircle(200,100, 20);
//
createCircle(300,100, 50,0x0000FF);