var LIGHT_RADIUS = 35;
var STOPLIGHT_WIDTH = 120;
var STOPLIGHT_HEIGHT = 350;
var DIST_BETWEEN_LIGHTS = 100;
var GRAY_COLOR = "#737071";

function start(){
	var stoplight = new Rectangle(STOPLIGHT_WIDTH, STOPLIGHT_HEIGHT);
	stoplight.setColor(GRAY_COLOR);
	stoplight.setPosition(getWidth()/2-60, getHeight()/2-175);
	add(stoplight);

	var getX = Color.red;
	var y = getHeight()/2-DIST_BETWEEN_LIGHTS;
	drawCircle(LIGHT_RADIUS, getX, getWidth()/2, y);

	getX = Color.yellow;
	var y = getHeight()/2;
	drawCircle(LIGHT_RADIUS, getX, getWidth()/2, y);

	getX = Color.green;
	var y = getHeight()/2+DIST_BETWEEN_LIGHTS;
	drawCircle(LIGHT_RADIUS, getX, getWidth()/2, y);
}

function drawCircle(radius, getX, x, y){
    var circle = new Circle(radius);
    circle.setColor(getX);
    circle.setPosition(x, y);
    add(circle);
}