Show the structure of Alert.

Example

<div class="alert alert-success"> 
<strong>Success!</strong> Indicates a successful or positive action.</div> 
<div class="alert alert-info">   
<strong>Info!</strong> Indicates a neutral informative change or action. </div>
 <div class="alert alert-warning">   
<strong>Warning!</strong> Indicates a warning that might need attention. </div> 
<div class="alert alert-danger">   
<strong>Danger!</strong> Indicates a dangerous or potentially negative action.</div>