[Jquery] Infinite scroll to load more

window.on('scroll', window_scroll_handler);

function window_scroll_handler() {
  var scrollPercent = window.scrollTop() / (document.height() - window.height());
  var scrollPercentRounded = (scrollPercent * 100);
  if (scrollPercentRounded > 94) {
      load_more();
  }
}

var isloading  = false;
var nextpage = 1;
function load_more() {
    if ( isloading === false) {
        // var url = "api.php?type=loadmore&page=" + this.nextpage;
        //這邊url,我們拿來測試到時要接正式的資料
        var url = "api.json";
        isloading = true;    
        $.getJSON("api.json",function(data) {
            if (data.html !== null && data.html.length > 0) {
                //這邊就是將資料撈取後放到哪個div 之下？？
                $('body').append(data.html);
                //針對每次scroll 會新增一個參數，讓頁面一直往下載入正確的內容
                nextpage++;
            }
            this.isloading = false;
        }).fail(function( jqxhr, textStatus, error ) {
            var err = textStatus + ", " + error;
            console.log( "Request Failed: " + err );
            //可以console出錯誤的訊息，避免做通靈王子
        });
      }
    }