Error While adding Dll

I m working in MVC 4 ..and after adding  dataannovation dll i m getting an error in global .asx. on following lines
            RegisterRoutes(RouteTable.Routes);             ModelBinders.Binders.DefaultBinder = new Microsoft.Web.mvc.DataAnnotations.DataAnnotationsModelBinder();

Error    1    The name 'RegisterRoutes' does not exist in the current context    C:\Webs\MVCStoreProcedure\MVCStoreProcedure\Global.asax.cs    27    13    MVCStoreProcedure
Error    2    The type or namespace name 'Mvc' does not exist in the namespace 'Microsoft.Web' (are you missing an assembly reference?)    C:\Webs\MVCStoreProcedure\MVCStoreProcedure\Global.asax.cs   & ...