hierarchy

[niloofar]

hi
i want to use hierarchy property
in search i wrote these code:
  protected void btnSearch_Click(object sender, EventArgs e)
        {
            grdShareHolder.DataSource = ResultSearch().AsQueryable();
            grdShareHolder.DataBind();
            grdShareHolder.MasterTableView.DetailTables[0].DataSource = ResultNewSearch();
        }
 private IQueryable<CDSStockDataAccess.tS004RegistChange> ResultNewSearch()
        {
            IQueryable<CDSStockDataAccess.tS004RegistChange> shareHolders = CDSStockLogic.BusinessObjects.UI.RegistChanges.Retrieve(  ?????);
            return shareHolders;
        }

   private IQueryable ResultSearch()
        {
            CDSStockLogic.BusinessObjects.UI.MatchExpression expression = new CDSStockLogic.BusinessObjects.UI.MatchExpression();
            if (txtLastName.Text.Trim() != string.Empty)
                expression.FamilyExpression = string.Format("%{0}%", this.txtLastName.Text.Trim());
            if (txtBoorsCode.Text.Trim() != string.Empty)
                expression.BoorsCodeExpression = string.Format("%{0}%", this.txtBoorsCode.Text.Trim());
            if (txtFirstName.Text.Trim() != string.Empty)
                expression.NameExpression = string.Format("%{0}%", this.txtFirstName.Text.Trim());
            if (txtNationalCode.Text.Trim() != string.Empty)
                expression.NationalCode = string.Format("{0}", this.txtNationalCode.Text.Trim());
            if (txtID.Text.Trim() != string.Empty)
                expression.IDExpression = string.Format("{0}", this.txtID.Text.Trim());
            if (txtFatherName.Text.Trim() != string.Empty)
                expression.FatherNameExpression = string.Format("%{0}%", this.txtFatherName.Text.Trim());
            if (txtIdNo.Text.Trim() != string.Empty)
                expression.IdNo = string.Format("{0}", this.txtIdNo.Text.Trim());
            IQueryable shareHolders = CDSStockLogic.BusinessObjects.UI.ShareHolder.Retrieve(expression);
            return shareHolders;
        }
how can i get datakeyname in  ResultNewSearch?
please help

[niloofar]

thanks
i solved it