         description:  @model.get('description')
         #image: if @node.get('image') then @node.get('image').huge.url else null
       }
+      index = parseInt @model.get('number')
       @$el.find('.panel-body .index-content, .panel-heading .index-header').addClass 'hide'
       @$el.find('.panel-body .chapter-content, .panel-heading .chapter-header').removeClass 'hide'
       @$el.find('.panel-body .chapter-content').html template
       @$el.find('.panel-heading .chapter-header .chapter-index').html @model.get('number')
+      # Show/hide prev/next arrows
+      @$el.find('.chapter-navigation').removeClass 'invisible'
+      if index == 1
+         @$el.find('.chapter-navigation-prev').addClass 'invisible'
+      else if index == @chaptersLength
+         @$el.find('.chapter-navigation-next').addClass 'invisible'
     else
       @$el.find('.panel-body .index-content, .panel-heading .index-header').removeClass 'hide'
       @$el.find('.panel-body .chapter-content, .panel-heading .chapter-header').addClass 'hide'


class StoryInfo extends Backbone.View

  el: '.story-info'

  initialize: ->
    # Show panel when click story-info btn
    $('.visualization-graph-menu-actions .btn-story-info').click @onBtnStoryInfoClick
    # Hide panel when click close btn

  onChapterNavigationClick: (e) =>
    e.preventDefault()
    index = if $(e.target).hasClass('chapter-navigation-next') then @model.get('number')+1 else @model.get('number')-1
    @$el.find('.chapters-list li:nth-child('+index+') a').trigger 'click'

  onChapterNavigationChildrenClick: (e) ->
