<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="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<div class="container">
<form class="well form-horizontal" action=" " method="post" id="contact_form">
<fieldset>
<legend>Contact Us</legend>
<div class="form-group">
<label class="col-md-4 control-label">First Name</label>
<div class="col-md-4 inputGroupContainer">
<div class="input-group">
<span class="input-group-addon"><i class="glyphicon glyphicon-user"></i></span>
<input name="first_name" placeholder="First Name" class="form-control" type="text">
</div>
</div>
</div>
<div class="form-group">
<label class="col-md-4 control-label" >Last Name</label>
<div class="col-md-4 inputGroupContainer">
<div class="input-group">
<span class="input-group-addon"><i class="glyphicon glyphicon-user"></i></span>
<input name="last_name" placeholder="Last Name" class="form-control" type="text">
</div>
</div>
</div>