let y;

​

function setup() {

  createCanvas(800, 400);

  x = width/2;

  y = height/2;

}

​

function draw() {

  background(220);

  line (200,100,600,100)

  line (200,300,200,100)

  line (600,100,600,300)

  line (600,300,200,300)

}

​