Load comments only if user viewed

isScrolledIntoView.js

// http://stackoverflow.com/a/488073
function isScrolledIntoView(elem)
{
    var docViewTop = $(window).scrollTop();
    var docViewBottom = docViewTop + $(window).height();

    var elemTop = $(elem).offset().top;
    var elemBottom = elemTop + $(elem).height();

    return ((elemBottom <= docViewBottom) && (elemTop >= docViewTop));
}

var comments_loaded = false;

$( window ).scroll(function() {
  if(isScrolledIntoView('#comments_form')){
    if(comments_loaded == false){
       // load_comments();
       comments_loaded = true;
    }
  }
});