var size = 10;

var n = 0;

var y = 0;

var yHold = 0;

function setup() {

  createCanvas(400, 400);

  frameRate(30);

  noStroke();

}

​

function draw() {

  background(220);

  speed = size/2

  raindrop();

  n++;

}

​

function raindrop(){

  ellipse(yHold, n*speed, size,size);

}