var imagestoload = new Array(
  "images/pictures/01.png",
  "images/pictures/02.png",
  "images/pictures/03.png",
  "images/pictures/04.png",
  "images/pictures/05.png",
  "images/pictures/06.png",
  "images/pictures/07.png",
  "images/pictures/08.png",
  "images/pictures/09.png",
  "images/pictures/10.png",
  "images/pictures/11.png",
  "images/pictures/12.png"
)

preImages = new Array()

function preloadImages() {
  for (i=0; i<=imagestoload.length; i++) {
    preImages[i] = new Image();
    preImages[i].src = imagestoload[i];
  }
}