var depth = _root.getNextHighestDepth();
var square = _root.createEmptyMovieClip("Example", depth);

square.beginFill(0x0022CC, 80);
square.lineStyle(2, 0xFF9900, 100);
square.moveTo(0, 0);
square.lineTo(100, 0);
square.lineTo(100, 100);
square.lineTo(0, 100);
square.lineTo(0, 0);
square.endFill();