javascript - Scroll to div on input keyup, keydown -

i trying page scroll specific div element when typing text input. nav has fixed position , item.offset().top output 2859, page not scroll. here code:

$('nav').on('keyup, keydown','input[name=search]',function(){     var search = $('input[name=search]').val(),         name = '',         item = '',         searchoff = false,         len = search.length;     if(len>2){         $('.products li').each(function(){             item = $(this);             name = item.find('p.left').text().substring(0,len).tolowercase();             if (name==search && searchoff==false){                 console.log(item.offset().top);                 $('body, html').animate({scrolltop:item.offset().top},'slow');                 searchoff=true;             }         });     } }); 

any ideas?