function nsLookup(host) { $.ajax({ type: 'GET', url: 'https://dns.google/resolve?name=' + host, dataType: 'json', success: function (result) { if (result.Answer) { if (result.Answer.length > 0) { $('div[data-cloud-server="' + host + '"] i').removeClass('c-5'); $('div[data-cloud-server="' + host + '"] i').addClass('c-7'); } } } }); } nsLookup('cs1.twisterarmy.org');