protected void gvParticipants_ItemCommand(object sender, Telerik.Web.UI.GridCommandEventArgs e)
        {
            switch (e.CommandName)
            {
            case "EditCustome":
                hdnItemId.Value = e.CommandArgument.ToString();
                var examiner = ExamBusiness.ListAllExamClassParticipants(id: Convert.ToInt32(e.CommandArgument)).Rows[0];
                txtExaminerName.Text             = examiner["ExaminerName"].ToString();
                ddlExaminerPlaceId.SelectedValue = examiner["ExaminerPalceId"].ToString();
                txtUserName.Text      = examiner["ExaminerUserName"].ToString();
                txtPassword.Text      = examiner["password"].ToString();
                btnCancelEdit.Visible = true;
                break;

            case "DeleteExaminer":
                ExamBusiness.DeleteExamClassParticipants(id: Convert.ToInt32(e.CommandArgument));
                BindGrid();
                break;
            }
        }