example/views/new_user.erb
<h3>Register a User</h3>
<% if @user.errors.any? %>
<ul class="errors">
<% @user.errors.full_messages.each do |message| %>
<li><%= message %></li>
<% end %>
</ul>
<% end %>
<form method="post" action="/users/create">
<fieldset>
<label for="name">Username</label>
<input type="text" name="username" id="username">
</fieldset>
<fieldset>
<input type="submit" value="Register">
</fieldset>
</form>