var Headers = Class.create({
    
    initialize: function(images) {
        this.images = images || new Array();
        this.current = 0;
        
        if(this.images.length <= 1) {
            return;
        }

        this.images.each(function(image, index) {
            if (index > 0) {
                image.hide();
            }
        });

        new PeriodicalExecuter(this.swap.bind(this), 4);
    },

    swap: function() {
        this.images[this.current].fade();
        this.current = this.current + 1;
        if (this.current >= this.images.length) {
            this.current = 0;
        }
        this.images[this.current].appear();
    }

});

function initHeaders() {
    $$('.content .header, .content-sub .header').each(function(obj) {
        new Headers(obj.getElementsBySelector('img'));
    });
}

document.observe('dom:loaded', initHeaders);