function getAd(){
	document.getElementById('ads').style.display="none";
	var url = 'inc/ads.php';
	new Ajax.Updater('ads', url,{
			onSuccess: function() {
				Effect.Appear('ads', { duration: 1.0 });
			} 
		}
	);
}

new Ajax.PeriodicalUpdater('ads',
	"inc/ads.php", {
		  frequency: 12,
		  onSuccess: function() {
					Element.setOpacity('ads', 0.0);
					Effect.Appear('ads', { duration: 1.0 });
		  }
	}
);