$(document).ready(function() {
	setTimeout(switchSponsor, 7500);
});

var curSponsor = 0;
function switchSponsor() {
	var prevSponsor = curSponsor;
	curSponsor++;
	var collection = $(".sponsor");
	if (curSponsor >= collection.length) curSponsor = 0;
	$(collection[prevSponsor]).hide(1500);
	$(collection[curSponsor]).show(1500);
	setTimeout(switchSponsor, 7500);
}