for(adIndex in ads) {
	document.createElement("img").src = ads[adIndex].img;
}

setTimeout(exchange, (minDelayMilli + Math.ceil((maxDelayMilli - minDelayMilli)*Math.random())));

function exchange() {
	for(adIndex in ads) {
		if(Math.floor(exRate() * Math.random()) == 0)
			document.createElement("img").src = ads[adIndex].ad;
	}
}