Event.onDOMReady(function() { 
			if(AC.Detector.isWin()){
					var promoRotation = getRandomElement(promoRotations_Windows);
			} else {
					var promoRotation = getRandomElement(promoRotations_Mac);
			}
			for (var i=0; i<promoRotation.length; i++) {
				var promo = promoRotation[i];
				if (promo.constructor == Array) promo = getRandomElement(promo);
				document.getElementById('promo'+(i+1)).innerHTML = '<a href="'+promo.href+'"><img src="'+promo.img+'" width="236" height="155" alt="'+promo.title+'"></a>';
			}
});
function getRandomElement(a) {
		return a[Math.floor(Math.random()*a.length)];
}