createCanvas(400, 400);

}

​

function draw() {

  background(0);

  noFill();

  stroke(255);

  strokeWeight(3);

  if((mouseX > width/2 - 50) && (mouseX < width/2 + 50) && (mouseY > height/2 - 50) && (mouseY < height/2 + 50)) {

     fill(168, 228, 230);

  }

  rect(width/2, height/2, 100, 100);

  rectMode(CENTER);

}