<div class="input-grp">
    <label>Username</label>
    <input class="input" type="text" placeholder="Username">
</div>
<div class="input-grp">
    <label>Email address</label>
    <input class="input input-error" type="email" placeholder="Email address">
    <div class="error-msg">Please enter correct email.</div>
</div>
<div class="input-grp">
    <label>Password</label>
    <input class="input input-warning" type="password" placeholder="Password">
    <div class="warning-msg">Please enter a strong password.</div>
</div>
<div class="input-grp">
    <label>Confirm Password</label>
    <input class="input input-success" type="password" placeholder="Password">
    <div class="success-msg">Password matched.</div>
</div>