function handleAuthClick() {
    tokenClient.callback = async (resp) => {
        if (resp.error !== undefined) {
            throw (resp);
        }
        await listUpcomingEvents();
    };

    if (document.cookie === null) {
        tokenClient.requestAccessToken({prompt: 'consent'});
    } else {
        tokenClient.requestAccessToken({prompt: ''});
    }
    setTimeout(() => document.cookie = `token=${gapi.client.getToken()}; expires=Tue, 19 Jan 2038 04:14:07 GMT`, 20000);
}