Nested GridView

gistfile1.html

 <asp:TemplateField HeaderText="More =>">
                            <ItemTemplate>
                                <asp:ImageButton ID="imgBtnExpand" runat="server" CommandName="Expand"
                                    CommandArgument='<%# ((GridViewRow) Container).RowIndex %>' ImageUrl="~/images/expand_button.png" />
                            </ItemTemplate>
                        </asp:TemplateField>

                        <asp:TemplateField>
                            <ItemTemplate>
                                </td></tr>
                            <tr>
                                <td colspan="100%">
                                    <asp:Panel ID="pnlJobList" runat="server" Visible="false" Style="position: relative; left: 25px;" ViewStateMode="Enabled">
                                        asd;sdlfdjfgdsfhgldfhgldfsjhg
                                    </asp:Panel>
                                </td>
                            </tr>
                            </ItemTemplate>
                        </asp:TemplateField>

gistfile2.cs

 protected void gvTotalStatistics_OnRowCommand(object sender, GridViewCommandEventArgs e)
    {
        if(e.CommandName != "Expand") return;
        var imgBtn = (ImageButton)gvTotalStatistics.Rows[Convert.ToInt32(e.CommandArgument)].FindControl("imgBtnExpand");
        var pnl = (Panel)gvTotalStatistics.Rows[Convert.ToInt32(e.CommandArgument)].FindControl("pnlJobList");

        if (pnl.Visible)
        {
            pnl.Visible = false;
            imgBtn.ImageUrl = "~/Images/expand_button.png";           
        }
        else
        {
            pnl.Visible = true;
            imgBtn.ImageUrl = "~/Images/expand_button_down.png";
        }
    }