Basic pattern for displaying content once per user

cookies_pattern.js

/* Basic pattern for displaying content once per user
   using http://code.google.com/p/cookies/ plugin.
*/

$(function(){
  var lightbox_cookie = $.cookies.get('lightbox_shown');
  var $lightbox = $('iframe#warriors_lightbox, div#warriors_overlay');
  if (lightbox_cookie == null) {
    $lightbox.fadeIn(300, function(){
      $.cookies.set( 'lightbox_shown', 'true' );
    });	      
  }
  var lightbox_close = $('iframe#warriors_lightbox").contents().find("a.close-button');
  lightbox_close.click(function(e){
    $lightbox.fadeOut(300);
    e.preventDefault();
  });
});