function setup() {

  createCanvas(400, 400);

    var newPatternButton = createButton("New Pattern");

  newPatternButton.mousePressed(pattern);

  newPatternButton.position(0, height - 0);

  var saveImageButton = createButton("Save Image");

  saveImageButton.mousePressed(saveImage);

  saveImageButton.position(120, height - 0);

   pattern();

}

​

function saveImage() {

  save("pattern.jpg");

}

function pattern() {

 background(220);

  for (let x = 0; x <= width; x += 50){ 

    var r = random(0, 255);

    var g = random(0, 100);

    var b = random(0, 100);

    fill(r, g, b);

    noStroke();

    ellipse(random(width), random(height),40);

  }

}