Can I get a value from a textbox which is in asp:DataGrid which is inside another asp:DataGrid's TemplateColumn in Javascript?

Question

I have a asp:DataGrid (Assume as Grid A) which has several asp:BoundColumn and asp:TemplateColumn inside.. One of the asp:TemplateColumn has another asp:DataGrid (Assume as Grid B)inside it , I want to get a value from a textbox onkeyup which is in Grid B and return it after calculation using Javascript or JQuery..

  <asp:DataGrid ID="dgfloor" runat="server" AutoGenerateColumns="False" CssClass="table table-bordered table-striped mb-0"
                                        ShowFooter="true" Width="100%">
                                        <PagerStyle HorizontalAlign="Right" NextPageText="Next" PrevPageText="Prev" />
                                        <Columns>

  <asp:DataGrid ID="dgfloor" runat="server" AutoGenerateColumns="False" CssClass="table table-bordered table-striped mb-0"
                                        ShowFooter="true" Width="100%">
                                        <PagerStyle HorizontalAlign="Right" NextPageText="Next" PrevPageText="Prev" />
                                        <Columns>
    <asp:BoundColumn DataField="Data1" HeaderText="Already Completion%" HeaderStyle-HorizontalAlign="Center" ItemStyle-HorizontalAlign="Center" HeaderStyle-Width="100px"></asp:BoundColumn>
   <asp:TemplateColumn HeaderText="Current Completion%" ItemStyle-HorizontalAlign="Center" HeaderStyle-HorizontalAlign="Center" ItemStyle-Width="100px">
                                                                <ItemTemplate>
                                                                    <asp:TextBox ID="txtData2" Width="70" runat="server" Text='<%#Eval("Percentage") %>' />
                                                                </ItemTemplate>
                                                            </asp:TemplateColumn>
   <asp:TemplateColumn HeaderText="Completion Amount" ItemStyle-HorizontalAlign="Center" HeaderStyle-HorizontalAlign="Center" ItemStyle-Width="100px">
                                                                <ItemTemplate>
                                                                    <asp:Label ID="lblData3" Text='<%#Eval("Completionamt") %>' runat="server"></asp:Label>
                                                                </ItemTemplate>
                                                            </asp:TemplateColumn>
 </Columns>

  </Columns>
  

 <script type="text/javascript">
        var grid = document.getElementById("<%= dgwork.ClientID %>");
        for (var i = 1; i < grid.rows.length; i++) {
            var grid2 = grid.rows[i].cells[6].childNodes[0].value;

            for (var i = 1; i < grid2.rows.length; i++) {
               

                var one = grid2.rows[i].cells[7].childNodes[0].value;
                alert(one);

            }
           
           
        }

        </script>

To test it I have tried this JS to check whether its getting the value from the Grid B but it dint work..

The actual thing is i need to get the value from grid b and calculate it

when I change the value in Current Completion% textbox it should calculate Already Completion%*Amount and display it in Completion Amount (calculations should be done in script)