diff --git a/assets/javascripts/app.js b/assets/javascripts/app.js
index 7d0f6cc..4af2a74 100644
--- a/assets/javascripts/app.js
+++ b/assets/javascripts/app.js
@@ -8,7 +8,9 @@
     // if (location.href.search('editmode') == -1 && document.getElementsByClassName('asideright').length != 0) {
     if ( $('.header-banner').length != 0) {
       $('.layout-header').css('height', '');
-      if ($(window).scrollTop() > 50)  {          /* 要滑動到選單的距離 */
+      var scrollTop = $(window).scrollTop();
+      var scrollBottom = $('html').height() - $(window).height() - scrollTop - $('.kenjohn').height();
+      if (scrollTop>50 && scrollBottom>0)  {          /* 要滑動到選單的距離 */
         $('.kenjohn').addClass('navFixed').removeClass('navRel');   /* 幫選單加上固定效果 */
       } else {
         if ($('.header-banner').html().trim() == "") {