fetch('https://umaring.github.io/bdunahu.json')
    .then(function(ret) { return ret.json(); })
    .then(function(json) {
        document.getElementById('umaring-id').innerHTML = `<ul>
	<li> <a href=${json.prev.url}>${json.prev.name}</a> </li>
	<li> <span>←</span>
	<li> <a href="https://github.com/umacabal/umaring">umass ring</a> </li>
	<li> <span>→</span>
	<li> <a href=${json.next.url}>${json.next.name}</a> </li>
</ul>`
    })
    .catch(function() {});