var J = jQuery.noConflict(); //added this function and replaced all the $'s in this script with J's... it was conflicting with prototype. sweet!
    // wrap as a jQuery plugin and pass jQuery in to our anoymous function
   
    (function (J) {
        J.fn.cross = function (options) {
            return this.each(function (i) { 
                // cache the copy of jQuery(this) - the start image
                var JJ = J(this);
                
                // get the target from the backgroundImage + regexp
                var target = JJ.css('backgroundImage').replace(/^url|[\(\)'"]/g, '');

                // nice long chain: wrap img element in span
                JJ.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 (J.browser.msie || J.browser.mozilla) {
                    JJ.css({
                        'position' : 'absolute', 
                        'left' : 0,
                        'background' : '',
                        'top' : this.offsetTop
                    });
                } else if (J.browser.opera && J.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...                    
                    JJ.css({
                        'position' : 'absolute', 
                        'left' : 0,
                        'background' : '',
                        'top' : "0"
                    });
                } else { // Safari
                    JJ.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
                JJ.hover(function () {
                    JJ.stop().animate({
                        opacity: 0
                    }, 250);
                }, function () {
                    JJ.stop().animate({
                        opacity: 1
                    }, 250);
                });
            });
        };
        
    })(jQuery);
    
    // note that this uses the .bind('load') on the window object, rather than J(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.
    J(window).bind('load', function () {
        J('img.fade').cross();
    });