/*$(document).ready(function() {
  $("#topo ul li img").hover(function() {
    $(this).attr("src", $(this).attr("src").split(".").join("_hover."));
  }, function() {
    $(this).attr("src", $(this).attr("src").split("_hover.").join("."));
  });
});*/

(function ($) {
  $.fn.cross = function (options) {
	  return this.each(function (i) { 
		  // cache the copy of jQuery(this) - the start image
		  var $$ = $(this);
		  
		  // get the target from the backgroundImage + regexp
		  var target = $$.css('backgroundImage').replace(/^url|[\(\)'"]/g, '');

		  // nice long chain: wrap img element in span
		  $$.wrap('<span style="position: relative;"></span>')
			  // change selector to parent - i.e. newly created span
			  .parent()
			  // prepend a new image inside the span
			  .prepend('<img>')
			  // change the selector to the newly created image
			  .find(':first-child')
			  // set the image to the target
			  .attr('src', target);

		  // the CSS styling of the start image needs to be handled
		  // differently for different browsers
		  if ($.browser.msie || $.browser.mozilla) {
			  $$.css({
				  'position' : 'absolute', 
				  'left' : 0,
				  'background' : '',
				  'top' : this.offsetTop
			  });
		  } else if ($.browser.opera && $.browser.version < 9.5) {
			  // Browser sniffing is bad - however opera < 9.5 has a render bug 
			  // so this is required to get around it we can't apply the 'top' : 0 
			  // separately because Mozilla strips the style set originally somehow...                    
			  $$.css({
				  'position' : 'absolute', 
				  'left' : 0,
				  'background' : '',
				  'top' : "0"
			  });
		  } else { // Safari
			  $$.css({
				  'position' : 'absolute', 
				  'left' : 0,
				  'background' : ''
			  });
		  }

		  // similar effect as single image technique, except using .animate 
		  // which will handle the fading up from the right opacity for us
		  $$.hover(function () {
			  $$.stop().animate({ opacity: 0 }, 250);
		  }, function () {
			  $$.stop().animate({ opacity: 1 }, 250);
		  });
	  });
  };
  
})(jQuery);

// note that this uses the .bind('load') on the window object, rather than $(document).ready() 
// because .ready() fires before the images have loaded, but we need to fire *after* because
// our code relies on the dimensions of the images already in place.
$(window).bind('load', function () {
  $('img.fade').cross();
});