let direction;

//add event to read users input then change direction
document.addEventListener('keydown', (e) => {
    if(e.keyCode == 37 && direction != 'right') direction = 'left';
    else if (e.keyCode == 38 && direction != 'down') direction = 'up';
    else if (e.keyCode == 39 && direction != 'left') direction = 'right';
    else if (e.keyCode == 40 && direction != 'up') direction = 'down';
})