1.Add this line to your application's Gemfile:-
gem 'jQuery-Validation-Engine-rails'
install:-
bundle
or
gem install jQuery-Validation-Engine-rails
2.CSS-application.css:-
*= require validationEngine.jquery
3. JS application.js:-
//= require jquery.validationEngine-en
//= require jquery.validationEngine
4.Form field:-
<form class="form_id">
<%= f.text_field :name, :class => "span2 validate[required] text-input" %>
or
<%= f.text_field :name, :class => "validate[required,custom[email]]" %>
<form>
<script type="text/javascript">
$(document).ready(function(){
$("#form_id").validationEngine();
});
</script>