MVC Unobtrusive Client Validation

Download and include jquery.validate.min.js and jquery.validate.unobtrusive.min.js

In web.config add:

 
<appSettings>
    <add key="ClientValidationEnabled" value="true" />
    <add key="ValidationSettings:UnobtrusiveValidationMode" value="None" />
    <add key="UnobtrusiveJavaScriptEnabled" value="true" />
</appSettings>