private void StepCompanyLevelManagersEmployeeProcessGrid()
        {
            CompanyLevelsAddManagers model = new CompanyLevelsAddManagers(companyLevelsAddTDS);
            int companyLevelId = Int32.Parse(hdfCompanyLevelId.Value);

            // update rows
            if (Session["companyLevelManagersDummy"] == null)
            {
                foreach (GridViewRow row in grdEmployees.Rows)
                {
                    int employeeId = int.Parse(grdEmployees.DataKeys[row.RowIndex].Values["EmployeeID"].ToString());
                    bool selected = ((CheckBox)row.FindControl("cbxSelected")).Checked;

                    if (selected)
                    {
                        model.Update(companyLevelId, employeeId, selected);
                    }
                    else
                    {
                        model.Update(0, employeeId, selected);
                    }
                }

                model.Table.AcceptChanges();

                Session["companyLevelsAddTDS"] = companyLevelsAddTDS;
                Session["companyLevelManagers"] = companyLevelsAddTDS.CompanyLevelManagers;
                companyLevelManagers = companyLevelsAddTDS.CompanyLevelManagers;
            }
        }