<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>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css">
<div class="container">
<h2 class="text-center">Contact Us</h2>
<div class="errors">
</div>
<form action="<?=$_SERVER['PHP_SELF']?>" class="contact-form" method="POST">
<div class="form-group">
<input type="text" name="username" id="username" class="username form-control" placeholder="Your Username" value="">
<i class="fa fa-user"></i>
<span class="asterix">*</span>
<span class="cross">x</span>
<span class="verify"><i class="fa fa-check" aria-hidden="true"></i></span>
<div class="alert alert-danger custom-alert">
user must be more than 3 letter
</div>
</div>
<div class="form-group">
<input type="text" name="email" class=" email form-control" placeholder="Your Email" value="">
<i class="fa fa-envelope"></i>
<span class="asterix">*</span>
<span class="cross">x</span>
<span class="verify"><i class="fa fa-check" aria-hidden="true"></i></span>
<div class="alert alert-danger custom-alert">
Email can not be empty
</div>
</div>
<div class="form-group">
<input type="text" name="subject" class="subject form-control" placeholder="Your subject" value="">