I have an alert box to confirm that the user has successfully subscribed:

```
<div className="alert alert-success">
    <strong>Success!</strong> Thank you for subscribing!
</div>    

```

When a user sends an email, I'm changing the "subscribed" state to true.

What I want is to:

* Show the alert box when the subscribed state is true
* Wait for 2 seconds
* Make it fade out

How can I do this?