<asp:DetailsView ID="DetailsView3" runat="server" Height="50px" Width="179px" AutoGenerateRows="False" DataKeyNames="begindate" DataSourceID="SqlDataSource3">        
            <EmptyDataTemplate>
                <asp:LinkButton ID="LinkButton2" runat="server" CommandName="New">Добавить</asp:LinkButton>
            </EmptyDataTemplate>
            <Fields>
                <asp:TemplateField >
                    <InsertItemTemplate>
                    Дата начала
                         <asp:TextBox ID="TextBox1" runat="server" Text='<%# Bind("begindate") %>' ValidationGroup="3"></asp:TextBox>
                        <asp:RangeValidator ID="RangeValidator1" runat="server" ControlToValidate="TextBox1"
                            ErrorMessage="Ошибочная дата" MaximumValue="01/01/2020" MinimumValue="01/01/2000"
                            Type="Date" ValidationGroup="3"></asp:RangeValidator>
                        <asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ControlToValidate="TextBox1"
                            ErrorMessage="Ошибочная дата" ValidationGroup="3"></asp:RequiredFieldValidator>                            
                    </InsertItemTemplate>                  
                </asp:TemplateField>
                <asp:CommandField ShowInsertButton="True" CancelText="Отмена" InsertText="Добавить" NewText="Новый" UpdateText="Записать" ValidationGroup="3" />
            </Fields>
        </asp:DetailsView>