Bootstrap 3 + Validation Plugin

HTML

<link rel="stylesheet" href="http://getbootstrap.com/dist/css/bootstrap.css">
<form role="form" method="POST" action="./newUser" name="newUserForm" id="newUserForm" style="position: relative; top:0px;left:0px; opacity: 1.0;">
    <div class="modal-body black-font">
        <div class="modal-body-form form-div form-signin">
            <div class="form-group">
                 <h4 class="form-signin-heading">Create an Account</h4>

                <input type="text" class="form-control top-buffer-sm" placeholder="Username" name="username" required autofocus></input>
                <input type="password" class="form-control top-buffer-sm" placeholder="Password" name="password" required></input>
                <input type="email" class="form-control top-buffer-sm" placeholder="Email" name="email" required autofocus></input>
            </div>
        </div>
    </div>
    <div class="modal-footer">
        <button id="createUserSubmit" type="submit" class="btn btn-primary">Create</button>
        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
    </div>
</form>

CSS

body {
    padding: 20px;
}