on page load how to full scroll down using jquery code example

Example 1: 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;
});

Example 2: how to interrupt scroll with jquery

$('body,html').bind('scroll mousedown wheel DOMMouseScroll mousewheel keyup touchmove', function (e) {
  if (e.which > 0 || e.type == "mousedown" || e.type == "mousewheel" || e.type == "touchmove") {
    $("html,body").stop();
  }
});