Linq to Sql Sum

        DSDataContext db = new DSDataContext();

        var bulldetail = from b in db.MilkingDetails
                         where b.CowNo == TextBox1.Text
                         select new { Total = ?????? };              
        GridView1.DataSource = bulldetail;
        GridView1.DataBind();
MilkingDetails has a column Total.. i wan to show the total. what should i write in place of ???

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