<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/js/bootstrap.min.js"></script>
<script src="//code.jquery.com/jquery-1.11.1.min.js"></script>
<div class="container">
<div class="main">
<div class="main-center">
<h5>Sign up once and watch any of our free demos.</h5>
<form class="" method="post" action="#">
<div class="form-group">
<label for="name">Your Name</label>
<div class="input-group">
<span class="input-group-addon"><i class="fa fa-user fa" aria-hidden="true"></i></span>
<input type="text" class="form-control" name="name" id="name" placeholder="Enter your Name"/>
</div>
</div>
<div class="form-group">
<label for="email">Your Email</label>
<div class="input-group">
<span class="input-group-addon"><i class="fa fa-envelope fa" aria-hidden="true"></i></span>
<input type="text" class="form-control" name="email" placeholder="Enter your Email"/>
</div>
</div>
<div class="form-group">
<label for="username">Username</label>
<div class="input-group">
<span class="input-group-addon"><i class="fa fa-users fa" aria-hidden="true"></i></span>
<input type="text" class="form-control" name="username" placeholder="Enter your Username"/>