var aryImages = new Array(2);

  aryImages[0] = "images/template/shirtdetails/losangeles.jpg";
  aryImages[1] = "images/template/shirtmodels/losangeles.jpg";
  
  for (i=0; i < aryImages.length; i++) {
    var preload = new Image();
    preload.src = aryImages[i];
  }

  function swap(imgIndex, imgTarget) {
    document[imgTarget].src = aryImages[imgIndex];
  }