//Set up a StringCollection object to hold the paths to the MDF and LDF files
            StringCollection files = new StringCollection();

           //Add the paths - depending on which database you want loaded
            files.Add(@"C:\\Program Files\\Microsoft SQL Server\\MSSQL.1\\MSSQL\\Data\\NBNData_Data.MDF"); 
            files.Add(@"C:\\Program Files\\Microsoft SQL Server\\MSSQL.1\\MSSQL\\Data\\NBNData_log.ldf"); 

           //Set up a connection string
            string connectionString = "Server=YourServerName\\SQLExpress;Trusted_Connection=Yes;";

          //Set up a connection
            SqlConnection connection =  new SqlConnection(connectionString);
            connection.Open();
            ServerConnection servConn = new ServerConnection(connection);

           //Set up a server object and connect to it
            Server sqlServer =  new Server(servConn);


           //Check if a database is attached first
           //If it's attached, detach it
                if (sqlServer.Databases.Contains("NBNData"))
                {
                    sqlServer.DetachDatabase("NBNData", false);


                    sqlServer.KillAllProcesses("NBNData");
                    sqlServer.Refresh();
                }

            //Attach the new database files
                sqlServer.AttachDatabase("NBNData", files, "YourServerName\\DBOwner",AttachOptions.None);
                   
                sqlServer.KillAllProcesses("NBNData");       
                sqlServer.Refresh();
         
            connection.Close();
         
            connection.Dispose();