     mobile:       true
     live:         true
     callback:     null
+    scrollContainer: undefined
 
   constructor: (options = {}) ->
     @scrolled = true
     @config   = @util().extend(options, @defaults)
+    if typeof options.scrollContainer is 'string'
+      @config.scrollContainer = document.querySelector(options.scrollContainer)
     # Map of elements to animation names:
     @animationNameCache = new WeakMap()
     @wowEvent = @util().createEvent(@config.boxClass)

  # unbind the scroll event
  stop: ->
    @stopped = true
    @util().removeEvent window, 'scroll', @scrollHandler
    @util().removeEvent window, 'resize', @scrollHandler
    clearInterval @interval if @interval?


  # check if box is visible
  isVisible: (box) ->
    offset     = box.getAttribute('data-wow-offset') or @config.offset
    viewTop    = (@config.scrollContainer && @config.scrollContainer.scrollTop) || window.pageYOffset
    viewBottom = viewTop + Math.min(@element.clientHeight, @util().innerHeight()) - offset
    top        = @offsetTop(box)
    bottom     = top + box.clientHeight
