revolvinglogos = Class.create();
revolvinglogos.applyTo('.sponsorList');
revolvinglogos.prototype = {
	initialize: function() {
		this.displayedLogo = 0;
		this.sponsors = this.getElementsByTagName('li');
	},
	runSlideshow: function() {
		new Effect.Fade(this.sponsors[this.displayedLogo]);
		new Effect.Fade(this.sponsors[this.addToDisplayedLogo(1)]);

		this.incrementDisplayedLogo(2);

		new Effect.Appear(this.sponsors[this.displayedLogo], {delay: 1});
		new Effect.Appear(this.sponsors[this.addToDisplayedLogo(1)], {delay: 1}, {delay: 1});
	},
	
	incrementDisplayedLogo: function(amount) {
		this.displayedLogo = this.addToDisplayedLogo(amount);
		if(this.displayedLogo >= this.sponsors.length) {
			this.displayedLogo = 0;
		}
	},
	addToDisplayedLogo: function(amount) {
		return (this.displayedLogo + amount) % this.sponsors.length;
	}
}

function slideshowRunner() {
	logos = document.getElementsByClassName('sponsorList');
	for(i = 0; i < logos.length; i++) {
		logos[i].runSlideshow();
	}
}

new PeriodicalExecuter(slideshowRunner, 10);