(function($) {
  var cache = [];
  // Arguments are image paths relative to the current page.
  $.preLoadImages = function() {
    var args_len = arguments.length;
    for (var i = args_len; i--;) {
      var cacheImage = document.createElement('img');
      cacheImage.src = arguments[i];
      cache.push(cacheImage);
    }
  }
})(jQuery)

jQuery.preLoadImages("/images/common/n1.jpg", "/images/common/n2.jpg", "/images/common/n3.jpg", "/images/common/n4.jpg", "/images/common/n5.jpg", "/images/common/n5_on.jpg", "/images/common/n4_on.jpg", "/images/common/n3_on.jpg", "/images/common/n2_on.jpg", "/images/common/n1_on.jpg");