function fullscreenPopupAd( options ) {

  var defaultOptions = {
    image_url: "",
    title: "Popup Ad",
    link_url: "/",
    hideIfCookieSet: true,
    cookieName: "viewedAd",
    cookieExpires: "7"
  };

  if (options)
  {
    options.image_url = ( options.image_url ) ? options.image_url : defaultOptions.image_url;
    options.title = ( options.title ) ? options.title : defaultOptions.title;
    options.link_url = ( options.link_url ) ? options.link_url : defaultOptions.link_url;
    options.hideIfCookieSet = ( options.hideIfCookieSet ) ? options.hideIfCookieSet : defaultOptions.hideIfCookieSet;
    options.cookieName =  ( options.cookieName ) ? options.cookieName : defaultOptions.cookieName;
    options.cookieExpires =  ( options.cookieExpires ) ? options.cookieExpires : defaultOptions.cookieExpires;
  }
  else
  {
    options = defaultOptions;
  }

  // Build the popup.
   var popupAd = $('<div class="popupAd">'),
       adContainer = $('<div class="adContainer">'),
       adLink = $('<a class="adLink"></a>'),
       adImg = $('<img class="adImage"/>'),
       closeBtn = $('<span class="closeAd">X</span>');
  
  if ( !options.hideIfCookieSet || !$.cookie( options.cookieName ) )
  {
    adLink.attr( 'href', options.link_url );
    adImg.attr( { 'src': options.image_url, 'alt':options.title } );

    if ( options.hideIfCookieSet )
    {
      $.cookie( options.cookieName, 'true', {expires: parseInt(options.cookieExpires), path: "/"} );
    }
    adLink.append( adImg );
    adContainer.append( adLink, closeBtn );
    popupAd.append( adContainer );
    $('body').append( popupAd );
  }

  $(closeBtn).click( function() {
    popupAd.hide();
  });
} // end fullscreenPopupAd