let speed = 0;

let accel = 0.2;

let bouncing=false;

function setup() { 

  createCanvas(400, 400);

} 

​

function draw() { 

  background(220);

  ellipse(200,ballY,20,20);

  function mousepress(){

  bouncing = !bouncing;

  }

  if (bouncing) {

  ballY=ballY+speed;

  speed = speed+accel;

  if (ballY > 395 || ballY< 0) {

    //print("ballY hits the ground");

   speed=0.95 * (speed*-1);

  }

  }

​

}