GA - user login

// Fire this dataLayer event when a user is redirected to the nexttraining.net website after logging in from the subdomain csi.slb.com login page. The event should fire only for successful logins.

<script>
window.dataLayer = window.dataLayer || [];
window.dataLayer.push({
 'event': 'login',
 'userId': '123456789'  // User ID from the website's database.
 });
</script>