seenit.js

$(document).on('fastclick', 'a[data-seenit]', function(evt){
  var key = $(this).attr('data-seenit');
  var after = $(this).attr('data-after-seenit-id')

  $("[data-seenit-target=" + key + "]").fadeOut();

  $.ajax('/seenit', {
    type : 'post',
    data : {
      key : key
    }
  });

  if(after){
    $('#' + after).fadeIn();
  }
})