index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" >
    
</head>
<style>
    body
    {
        background-color: rgb(233, 229, 229);
    }
.heading{
color: #fff;
background: rgb(136, 219, 27);
text-transform: uppercase;
padding: 20px;
font-size: 16px;
letter-spacing: 1px;
margin-bottom: 50px;
}
</style>
<body>
    <div class="container">
        <div class="row">
                <h2 class="heading">Javascript crud app</h2>

            <div class="add-user">
                 <div class="col-md-12">
                     <h4>Add user</h4>
                 </div>
                 <div class="col-md-10">
                       <input type="text" value="" class="form-control" id="data">
                    </div>
                 <div class="col-md-2">
                     <button type="button" class="btn btn-primary" onclick="addUser();"> Add User</button>
                 </div>


            </div>
        </div>


         <div class="row">
          <div class="col-md-12">
              <h4>User list</h4> 
          </div>
        </div>


        <div class="row" id="userList">
          
         </div>
    </div>

    <script src="index.js"> 
        </script>
</body>
</html>