Ti posto il codice:

Codice PHP:
         /* Before Slide Transition
        ----------------------------*/
         beforeAnimation : function(direction){
             $('#supersized .slide-'+vars.current_slide+' img')
            if (api.options.progress_bar && !vars.is_paused) $(vars.progress_bar).stop().animate({left : -$(window).width()}, 0 );
              
              /* Update Fields
              ----------------------------*/
              // Update slide caption
               if ($(vars.slide_caption).length){
                   (api.getField('title')) ? $(vars.slide_caption).html(api.getField('title')) : $(vars.slide_caption).html('');
               }
            // Update slide number
            if (vars.slide_current.length){
                $(vars.slide_current).html(vars.current_slide + 1);
            }
            
            
            // Highlight current thumbnail and adjust row position
            if (api.options.thumb_links){
            
                $('.current-thumb').removeClass('current-thumb');
                $('li', vars.thumb_list).eq(vars.current_slide).addClass('current-thumb');
                
                // If thumb out of view
                if ($(vars.thumb_list).width() > $(vars.thumb_tray).width()){
                    // If next slide direction
                    if (direction == 'next'){
                        if (vars.current_slide == 0){
                            vars.thumb_page = 0;
                            $(vars.thumb_list).stop().animate({'left': vars.thumb_page}, {duration:500, easing:'easeOutExpo'});
                        } else if ($('.current-thumb').offset().left - $(vars.thumb_tray).offset().left >= vars.thumb_interval){
                            vars.thumb_page = vars.thumb_page - vars.thumb_interval;
                            $(vars.thumb_list).stop().animate({'left': vars.thumb_page}, {duration:500, easing:'easeOutExpo'});
                        }
                    // If previous slide direction
                    }else if(direction == 'prev'){
                        if (vars.current_slide == api.options.slides.length - 1){
                            vars.thumb_page = Math.floor($(vars.thumb_list).width() / vars.thumb_interval) * -vars.thumb_interval;
                            if ($(vars.thumb_list).width() <= -vars.thumb_page) vars.thumb_page = vars.thumb_page + vars.thumb_interval;
                            $(vars.thumb_list).stop().animate({'left': vars.thumb_page}, {duration:500, easing:'easeOutExpo'});
                        } else if ($('.current-thumb').offset().left - $(vars.thumb_tray).offset().left < 0){
                            if (vars.thumb_page + vars.thumb_interval > 0) return false;
                            vars.thumb_page = vars.thumb_page + vars.thumb_interval;
                            $(vars.thumb_list).stop().animate({'left': vars.thumb_page}, {duration:500, easing:'easeOutExpo'});
                        }
                    }
                }
                
                
            }
            
         },
         
         
         /* After Slide Transition
        ----------------------------*/
         afterAnimation : function(){
             $('#supersized .slide-'+vars.current_slide+' img').stop().animate({'opacity':1},2500)
             if (api.options.progress_bar && !vars.is_paused) theme.progressBar();    //  Start progress bar
         }, 
Ho inserito solo la parte beforeAnimation e afterAnimation.

Non preoccuparti, se ti va e quando hai tempo.
Gentilissimo