createCanvas(400, 400);

}

​

function draw() {

  background(220);

​

    fill (20, 20, 20);

  noStroke();

  rect (180, 350, 50, 50)

  fill (50, 50, 50);

  noStroke();

  rect (130, 30, 150, 350)

noStroke ();

fill(0, 0, 0);

  //red light

if (mouseY < 100) {

  fill (255, 0, 0);

}

 ellipse (200, 100, 90, 90);

   //yellow light

if (mouseY < 200) {

  fill (255, 255, 0);

}

 ellipse (200, 200, 90, 90);

    //green light

if (mouseY < 300) {

  fill (0, 255, 0);

} 

 ellipse (200, 300, 90, 90);

​

}