Implementation
There will be a layout file (_Layout.cshtml) to define the layout structure of your web application. As JavaScript libraries are going to be used in all the pages, this is the right place to add common functionalities such as unobtrusive validation. Just add the JavaScript libraries (highlighted in bold) to the layout file (_Layout.cshtml) so that they will be available for all the View files:
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>@ViewBag.Title</title>
</head>
<body>
<div>
@RenderBody()
</div>
<script src="http://ajax.aspnetcdn.com/ajax/jQuery/jquery-2.2.3.js"></script>
<script src="https://ajax.aspnetcdn.com/ajax/jquery.validate/1.14.0/jquery.validate.min.js"></script>
<script src="https://ajax.aspnetcdn.com/ajax/mvc/5.2...
