img_preload = new Array();
img_loaded = new Array();

function img_addPreload(src) {
  img_preload[img_preload.length] = src;
}

function img_doPreload() {
  var i;
  var img;
  for (i=0; i < img_preload.length; i++) {
    img = new Image();
    img.src = img_preload[i];
    img_loaded[img_loaded.length] = img;
  }
}