var theImages = new Array();

theImages[0] = 'immagini/img_logo.png';
// theImages[1] = 'immagini/img_logo.png';

var i = 0;
var p = theImages.length;
var preBuffer = new Array();
for (i = 0; i < p; i++) {
  preBuffer[i] = new Image();
  preBuffer[i].src = theImages[i];
}