Ajax from PHP

CFBFeatures.js

var count = 2;
var loader = $('.infinite-loader');

$(window).scroll(function() {

  if($(window).scrollTop() == $(document).height() - $(window).height()) {

    if(count > total) {
      return false;
    } else {
      loadInfiniteContent(count);
    }

    count++;

  }

});

function loadInfiniteContent(pageNumber) {

  loader.fadeIn(500);

  $.ajax({

    url: '/wp-admin/admin-ajax.php',
    type: 'POST',
    data: 'action=infinite_scroll&page_no=' + pageNumber + '&loop_file=loop',
    success: function(html) { 
      var element = $(html);

      //preprocess HTML before inserting into DOM
      element.find('.article-container, .article-container-grid').each(function() {
      // IF ID DOES EXIST, ADD CLASS TO ARTICLE CONTAINER
      if(cookieValue.indexOf($(this).data('id')) != -1) {	
        $(this).addClass('readit');											

        if(!appended) {
          $('<h4 class="readit-alert">You&apos;ve read it!</h4>').appendTo('.article-container.readit, .article-container-grid.readit');
          appended = true;
        }

      } else {
        // OTHERWISE, ADD CLASS NOT READ
        $(this).addClass('notread');										
          appended = false;
        }
      });

      loader.fadeOut(500);
      $('#main-content').append(element);
    }

  });

  return false;

}

cfbfeatures.php

function wp_infinitepaginate(){
    $loopFile        = $_POST['loop_file'];
    $paged           = $_POST['page_no'];
    $posts_per_page  = get_option('posts_per_page');

    query_posts(array('paged' => $paged ));
    get_template_part( $loopFile );
    exit;
}