function getHeaderPicture()
{
  new Ajax.PeriodicalUpdater("empty-space", "/banner_updater.php", {
 // initial number of seconds interval between calls
 frequency : 10,
 decay : 2,
 onSuccess: function(req) {
		var json = req.responseText.evalJSON(true);
		
			var slika = json.slika;
			new Effect.Opacity
('header_image',{duration: 0.5, from: 1.0, to: 0.5, afterFinish: function() {
   			Element.setStyle('header_image',{'background':'transparent url(/uploads/banner/' + slika + ') no-repeat 0 0'});	
   			new Effect.Opacity('header_image',{duration:0.5, from: 0.5, to: 1.0});
}});
			
			
        }
});
}