action.coffee

try_go = (obj, func) ->
  moved = false
  console.log 'start'

  $(window).on 'unload', ->
    moved = true
    console.log 'unload'

  func()

  setTimeout ->
    unless moved
      console.log 'not moved'
      obj.removeClass('pressed')
      obj.addClass('disable')
  , 100

$('#header .app_nav .back a').click ->
  unless $(this).hasClass('disable')
    $(this).addClass('pressed')
    try_go $(this), -> history.back()
  false