nesting of gridview by kumaranilaggarwal

.aspx
<fieldset>
                    <legend style="color: #669900; font-size: medium; font-weight: bold">Factor</legend>
                    <div style="height: 600px; overflow: scroll;">
                        <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" CellPadding="4"
                            Width="100%" ForeColor="#333333" GridLines="None">
                            <RowStyle BackColor="#F7F6F3" ForeColor="#333333" CssClass="ll" />
                            <FooterStyle BackColor="#5D7B9D" ForeColor="White" Font-Bold="True" />
                            <PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
                            <SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
                            <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
                            <Columns>
                                <asp:TemplateField HeaderText="Factor" HeaderStyle-CssClass="ll">
                                    <ItemTemplate>
                                        <asp:HiddenField ID="Label2" runat="server" Value='<%# Eval("fact_id") %>'></asp:HiddenField>
                                        <asp:Label ID="lblfactor" runat="server" Text='<%# Eval("fact_desc") %>' Width="200"></asp:Label>
                                        <asp:TextBox ID="txtFactor" runat="server" Width="70"></asp:TextBox>
                                    </ItemTemplate>
                                    <HeaderStyle CssClass="ll"></HeaderStyle>
                                </asp:TemplateField>
                                <asp:TemplateField>
                                    <ItemTemplate>
                                        <asp:GridView ID="GridView2" runat="server" CssClass="ll" AutoGenerateColumns="false"
                                            Width="100%" ShowHeader="true">
                                            <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
                                            <Columns>
                                                <asp:TemplateField HeaderText="SubFactor" HeaderStyle-CssClass="ll">
                                                    <ItemTemplate>
                                                        <asp:HiddenField ID="Label21" runat="server" Value='<%# Eval("fact_dtl_id") %>' />
                                                        <asp:Label ID="Label1" runat="server" Text='<%# Eval("fact_dtl_desc") %>' Width="200"></asp:Label>
                                                        <asp:TextBox ID="txtSubFactor" runat="server" Width="70"></asp:TextBox>
                                                    </ItemTemplate>
                                                </asp:TemplateField>
                                                <asp:TemplateField>
                                                    <ItemTemplate>
                                                        <asp:GridView ID="GridView3" CssClass="ll" runat="server" AutoGenerateColumns="false"
                                                            Width="100%" ShowHeader="true">
                                                            <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
                                                            <Columns>
                                                                <asp:TemplateField HeaderText="SubFactorDetail" HeaderStyle-CssClass="ll">
                                                                    <ItemTemplate>
                                                                        <asp:HiddenField ID="Label2id" runat="server" Value='<%# Eval("fact_subdtl_id") %>' />
                                                                        <asp:Label ID="Label111" runat="server" Text='<%# Eval("fact_subdtl_desc") %>' Width="200"></asp:Label>
                                                                        <asp:TextBox ID="txtCalculation" runat="server" Width="70"></asp:TextBox>
                                                                    </ItemTemplate>
                                                                </asp:TemplateField>
                                                            </Columns>
                                                        </asp:GridView>
                                                    </ItemTemplate>
                                                </asp:TemplateField>
                                            </Columns>
                                        </asp:GridView>
                                    </ItemTemplate>
                                </asp:TemplateField>
                            </Columns>
                            <EditRowStyle BackColor="#999999" />
                            <AlternatingRowStyle BackColor="White" ForeColor="#284775" />
                        </asp:GridView>
                    </div>
                </fieldset>


.cs
 public void fill()
    {
        string s = "select * from fact_mst";
        ds = c1.selectds(s);
        GridView1.DataSource = ds;
        GridView1.DataBind();
        SecondGridBind();
    }

    protected void SecondGridBind()
    {
        foreach (GridViewRow row in GridView1.Rows)
        {
            HiddenField lblid = row.FindControl("Label2") as HiddenField;
            GridView GridView2 = row.FindControl("GridView2") as GridView;
            string str = "select * from  fact_dtl_mst where fact_id='" + lblid.Value + "'";
            ds = c1.selectds(str);
            GridView2.DataSource = ds;
            GridView2.DataBind();
            foreach (GridViewRow rows in GridView2.Rows)
            {
                HiddenField lblid3 = rows.FindControl("Label21") as HiddenField;
                GridView GridView3 = rows.FindControl("GridView3") as GridView;
                string str3 = "select * from  fact_subdtl_mst where fact_dtl_id='" + lblid3.Value + "'";
                ds = c1.selectds(str3);
                GridView3.DataSource = ds;
                GridView3.DataBind();

            }
        }
    }