$(document).ready(function(){
$("img.swapImg").hover(function() {
	this.offsrc= this.src;
	var extIndex= this.offsrc.lastIndexOf(".");
	this.onsrc=this.offsrc.substr(0,(extIndex-3))+"on"+this.offsrc.substr(extIndex,4);

	$(this).attr('src', function(){return this.onsrc; });
	} , function() {
	$(this).attr('src', this.offsrc);	
});
});

(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)