Delete ListItem using SharePoint Linq

Note:- Here Title is Primary Key.
var context = new LinqSampleDataContext(SPContext.Current.Web.Url);
            foreach (LoginItem item in context.Login)
            {
                if (item.Title == txtUserName.Text)
                {
                    context.Login.DeleteOnSubmit(item);
                }
            }

            context.SubmitChanges();
            this.Controls.Add(new LiteralControl("Record Successfully
Deleted"));