createCanvas(400, 400);

}

​

function draw() {

  fill(0,0,0);

  textSize(21);

  textAlign(CENTER);

  text("click to place a square",200,30);

  text("press r for red, g for green",200,55);

  text("b for blue, and 0 for black",200,80);

  if(key === 'r'){

    fill(255,0,0);

  }

  if(key === 'g'){

    fill(0,255,0);

  }

  if(key === 'b'){

    fill(0,0,255);

  }

  if(key === '0'){

    fill(0);

  }

}

function mouseClicked(){

  rect(mouseX - 15,mouseY - 15,30);

}

​