Declaring connection string in a class

Question

Hi,
   Declaring connection string  in a class which is declared in web.config file


if do like this showing an error Non Invocable member

using System.Data.SqlClient;

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Configuration;

namespace CSharpTutorial

{

        public class MyFunctClass

              

    {

           string connstr = ConfigurationManager.ConnectionStrings ("myConnectionString").connectionString;  

          

   

    }

}

Plz help