     #    if scrolled past bottom of element, position bottom of element at bottom of viewport
     #      (stick to bottom)
     update : -> 
+
+      if !@$el
+        console.error('sticky element has disappeared!!')
+        @destroy()
+        return
 
       container_top = @options.container.offset().top 
       viewport_top = (document.documentElement.scrollTop || document.body.scrollTop)


      # Don't need to do anything if we're not actually stuck
      return if !@is_stuck


      ######
      # HORIZONTAL ADJUSTMENTS


    destroy : -> 
      $(window).off ".plugin_stickytopbottom-#{@my_id}"
      $.removeData @$el[0], "plugin_stickytopbottom" if @$el
      @$el = null


