draw.js save scaffold

// ...
  id('pickerButton').addEventListener('click', () => PICKR.show());

  window.save = function(x, y) {
    var data = {};
    data['x'] = x;
    data['y'] = y;
    data['data'] = filledPixels;
    $.post('draw.php?submit=1', data, function(rsp) {
      $('body').append(rsp);
    });
  }

  function id(id) {
    return document.getElementById(id);
  }
});