<script src="http://spelprogrammering.nu/simple.js">
function start()
{
  ball = {x: 0, y: 0};
}

function update()
{
  clearScreen();

  if (keyboard.left)  { ball.x--; }
  if (keyboard.right) { ball.x++; }
  if (keyboard.up)    { ball.y--; }
  if (keyboard.down)  { ball.y++; }

  circle(ball.x, ball.y, 50, "red");
}
</script>