Grid with data key

<asp:GridView ID="gv" runat="server" Width="70%"   AutoGenerateColumns="false"
                    OnSelectedIndexChanged="gv_SelectedIndexChanged" DataKeyNames="Id">
                    <Columns>
                        <asp:CommandField ShowSelectButton="true" ItemStyle-Width="10pt" />
                        <asp:BoundField DataField="Name" HeaderText="Name" />
                    </Columns>
                </asp:GridView>