Canvas attachment for mischief

mischief.js

(function (document) {
  var canvas = document.createElement('canvas');
  canvas.style.width='100%';
  canvas.style.height='100%';
  canvas.style.top=0;
  canvas.style.left=0;
  canvas.style.position='absolute';
  document.body.appendChild(canvas);
  return canvas;
}(document));