// wrap as a jQuery plugin and pass jQuery in to our anoymous function
(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) {
	$$.css({
	'position' : 'absolute', 
	'left' : 0,
	'background' : '',
	'top' : 0
	});
	}else if ($.browser.mozilla) {
	$$.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
						   }, 200);
		 }, function () {
		 $$.stop().animate({
						   opacity: 1
						   }, 200);
		 });
	});
	};

	})(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();
});