MVC - Fix Error - The type or namespace name 'WebService' could not be found

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   The type or namespace name 'WebService' could not be found (are you missing a using directive or an assembly reference?)  

   The type or namespace name 'WebServiceAttribute' could not be found (are you missing a using directive or an assembly reference?)   

 The type or namespace name 'Namespace' could not be found (are you missing a using directive or an assembly reference?)   

I am getting this error with this code

   [WebService(Namespace = "http://microsoft.com/webserives/")]
    public class HomeController : Controller
    {

to fix it

add 

using System.Web.Services;