DropDownList validation inside GridView for selected CheckBox in jQuery

Hello all

I have a grid view where i have drop down list,when i click button(btnReserve) it checks  for all the drop down should be selected(not the default value any should be selected).

It is working fine, now i add check box inside the grid view and when i click button(btnReserve) only selected check box records should be check for drop down list select.

Hope you understand.

I have provided the code below.

 <asp:GridView ID="GVResrv" runat="server" Width="100%" AutoGenerateColumns="false"
    TabIndex="1" Font-Names="Times New Roman" Font-Size="Smaller" HeaderStyle-HorizontalAlign="Center">
    <Columns>
        <asp:CommandField ShowSelectButton="true" HeaderText="Details" SelectText="Details" />
        <asp:TemplateField>
            <HeaderTemplate>
                <asp:CheckBox ID="chkHeader" runat="server" Checked="true" />
            </HeaderTemplate>
            <ItemTemplate>
                <asp:CheckBox ID="chkRow" runat="server" Checked="true" />
            </ItemTemplate>
        </asp:TemplateField>
        <asp:BoundField DataField="Vin" HeaderText="VinNumber" />
        <asp:BoundField DataField="Model No_" HeaderText="Model No" />
        <asp:BoundField DataField="Model Year" HeaderText="Model Year" />
        <asp:BoundField DataField="Model Code" HeaderText="Model Code" />
        <asp:BoundField DataField="Color" HeaderText="Color" />
        <asp:BoundField DataField="Location" HeaderText="Location" />
        <asp:BoundField DataField="Status" HeaderText="Status" />
        <asp:TemplateField HeaderText="Sales Person">
            <ItemTemplate>
                <asp:TextBox ID="txtSalesPersonName" runat="server" Text='<%# Eval("Sales_Person_Name") %>' />
            </ItemTemplate>
            <ItemTemplate>
                <asp:DropDownList ID="ddlSalesPerson" CssClass="ddldp" runat="server" DataSourceID="SqlDataSource2"
                    DataTextField="SalesPersonName" DataValueField="SalesPersonName" AppendDataBoundItems="true">
                    <asp:ListItem Text="Select" Value="0" />
                </asp:DropDownList>
                <asp:SqlDataSource ID="SqlDataSource2" runat="server" ConnectionString="<%$ ConnectionStrings:VehicleConnectionString1 %>"
                    SelectCommand="Select SPNID,SalesPersonName from R_ResrvSalesPerson"></asp:SqlDataSource>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:BoundField DataField="Check_Remarks" HeaderText="Check Remarks" />
    </Columns>
</asp:GridView>

 <script src="Jquery/jquery-1.10.2.min.js" type="text/javascript"></script>
        <script type="text/javascript">
            $(document).ready(function () {
                $("[id$=btnReserveTest]").click(function () {
                    var flag = 1;
                    $('.ddldp').each(function () {
                        if ($('#' + this.id).val() == 0) {
                            flag = 0;
                        }
                    });
                    if (flag != 0) {
                        //Selected option from dropdownlist
                     
                        return true;
                    } else {
                        //Not selected so alert user to select any option
                        alert('Please select Sales Person Name');
                        return false;
                    }
                });
            });
    </script>