window scroll up jquery code example

Example 1: scroll to element jquery

$('html, body').animate({
  scrollTop: $("#grepperRocks").offset().top
});

Example 2: jquery on scroll down

Check current scrollTop vs previous scrollTop

var lastScrollTop = 0;
$(window).scroll(function(event){
   var st = $(this).scrollTop();
   if (st > lastScrollTop){
       // downscroll code
   } else {
      // upscroll code
   }
   lastScrollTop = st;
});