scroll event not working on mobile

var addition_constant = 0;
$(document.body).on('touchmove', onScroll); // for mobile
$(window).on('scroll', onScroll);

function onScroll() {
  var addition = ($(window).scrollTop() + window.innerHeight);

  var scrollHeight = (document.body.scrollHeight - 1);
  if (addition > scrollHeight && addition_constant < addition) {

    addition_constant = addition;

    loadmorecontest();
  }
}

Try this:

$(document.body).on('touchmove', onScroll); // for mobile
$(window).on('scroll', onScroll); 

// callback
function onScroll(){ 
    if( $(window).scrollTop() + window.innerHeight >= document.body.scrollHeight ) { 
        track_page++; 
        load_contents(track_page); 
    }
}