var curIndex = 0;
var contentEls = null;

var clearPrevious = function() {
	if(contentEls) {
		dojo.forEach(contentEls, function(el) {
			if(dojo.style(el, 'display') !== 'none') {
				dojo.style(el, 'display', 'none');
			}
		});
	}
};

var contentFwd = function() {
	if(contentEls) {
		curIndex++;
		curIndex = curIndex % contentEls.length;

		clearPrevious();
		dojo.style(contentEls[curIndex], {
			display: 'block',
			opacity: 0
		});
		dojo.fadeIn({node: contentEls[curIndex]}).play();
	}
};

var contentBack = function() {
	if(contentEls) {
		curIndex = (curIndex > 0 ? curIndex - 1 : contentEls.length - 1);

		clearPrevious();
		dojo.style(contentEls[curIndex], {
			display: 'block',
			opacity: 0
		});
		dojo.fadeIn({node: contentEls[curIndex]}).play();
	}
};

dojo.addOnLoad(function() {
	contentEls = dojo.query('li', 'content_container');
	curIndex = contentEls.length - 1;
	contentFwd();
});