how to get selected value of dropdownlist on nested grid row command

<asp:GridView ID="grid" EmptyDataText="No receipt book(s) found.!" runat="server"
        OnRowDataBound="grid_rowdatabound">
        <Columns>
            <%--SrNo--%>
            <asp:TemplateField HeaderText="No." HeaderStyle-Width="18px">
                <ItemTemplate>
                    <%# Container.DataItemIndex + 1 %>
                </ItemTemplate>
                <ItemStyle VerticalAlign="Middle" HorizontalAlign="Center" />
            </asp:TemplateField>
            <asp:TemplateField>
                <ItemTemplate>
                    <img alt="" style="cursor: pointer;" src="../images/plus.png" />
                    <asp:Panel ID="pnlChiled"  runat="server"
                        Style="display: none;" Width="800px">
                        <asp:GridView ID="gvReceipts" runat="server" AutoGenerateColumns="false" CssClass="gridview"
                            Width="500px" OnRowCommand="gridReceiptCopy_onRowcommand">
                            <HeaderStyle CssClass="gridviewHeader" />
                            <Columns>
                                <asp:TemplateField HeaderText="No." HeaderStyle-Width="18px">
                                    <ItemTemplate>
                                        <asp:Label ID="lblNo" runat="server" Text='<%#Eval("Number")%>'></asp:Label>
                                    </ItemTemplate>
                                </asp:TemplateField>
                                <asp:TemplateField HeaderText="Status" HeaderStyle-Width="50px" ItemStyle-Width="50px">
                                    <ItemTemplate>
                                        <asp:DropDownList ID="ddlReceiptCopyStatus" runat="server">
                                            <asp:ListItem Text="firstValue" Value="1"></asp:ListItem>
                                            <asp:ListItem Text="secondValue" Value="2"></asp:ListItem>
                                        </asp:DropDownList>
                                    </ItemTemplate>
                                </asp:TemplateField>
                                <asp:TemplateField>
                                    <ItemTemplate>
                                        <asp:LinkButton ID="lbtnSubmit" runat="server" CssClass="buttonfcr" CommandName="ChangeCopyStatus"
                                            Text="Submit"></asp:LinkButton>
                                    </ItemTemplate>
                                </asp:TemplateField>
                            </Columns>
                        </asp:GridView>
                    </asp:Panel>
                </ItemTemplate>
            </asp:TemplateField>
        </Columns>
    </asp:GridView>

protected void gridReceiptCopy_onRowcommand(object sender, GridViewCommandEventArgs e)
      {
          if (e.CommandName.Equals("ChangeCopyStatus"))
          {
              GridViewRow curruntRow = (GridViewRow)(((LinkButton)e.CommandSource).NamingContainer);

              DropDownList ddlCopyStatus = (DropDownList)curruntRow.FindControl("ddlReceiptCopyStatus") as DropDownList;//copystatus dropdownlist
              string selectedNewValue = ddlCopyStatus.SelectedItem.Text;
              //here i want to get the selectedValue
          }
      }