Doesnt run JS if active element doesnt exist

app/assets/javascripts/layout_nav.js

@@ -29,14 +29,17 @@
       var $this = $(this),
           scrollingTabWidth = $this.width(),
           $active = $this.find('.active'),
-          activeWidth = $active.width(),
-          offset = $active.offset().left + activeWidth;
+          activeWidth = $active.width();
+
+      if ($active.length) {
+        var offset = $active.offset().left + activeWidth;
 
         if (offset > scrollingTabWidth - 30) {
           var scrollLeft = scrollingTabWidth / 2;
           scrollLeft = (offset - scrollLeft) - (activeWidth / 2);
           $this.scrollLeft(scrollLeft);
         }
+      }
     });
   });