Alert – Alerts with simple content or internal sections and HTML tags.

From Bootstrap - Demo Wiki
Component
Name Alert
Description Alerts with simple content or internal sections and HTML tags.
Provider Skin
Reference getbootstrap.com - alerts
Styling For all possible color styles and corresponding examples, see colors.

Basic Alert

Code
<div class="alert alert-primary" role="alert">
This is a primary alert — check it out!
</div>
Result

Alert with a link

Code
<div class="alert alert-warning" role="alert">
This is an alert with [[Alert|'''an example link''']]. Give it a click if you like.
</div>
Result

Additional HTML content

Code
<div class="alert alert-success" role="alert">
<h3 class="alert-heading">Well done!</h3>
Yeah, you successfully read this important alert message. This example text is going to run a bit longer so that you can see how spacing within an alert works with this kind of content.
<hr>
Whenever you need to, be sure to use margin utilities to keep things nice and tidy.
</div>
Result