listview issue

Hi

little bit changes in your code, try this

<asp:UpdatePanel ID="UpdatePanel1" runat="server">

            <ContentTemplate>

                <asp:ListView ID="lstview" runat="server" DataSourceID="orderdatasource">

                    <LayoutTemplate>

                        <table id="itemplaceholdercontainer">

                            <tr>

                                <td>

                                    <th>

                                        Order ID

                                    th>

                                    <th>

                                        Customer ID

                                    th>

                                    <th>

                                        Order Date

                                    th>

                                    <th>

                                        Ship Address

                                    th>

                                    <th>

                                        Ship Country

                                    th>

                                td>

                            tr>

                            <tr runat="server" id="itemPlaceholder">

                                <td>

                                td>

                            tr>

                        table>

                        <table>

                            <tr>

                                <td>

                                    <asp:Label ID="lblorderid" runat="server" Text='<%#eval(orderid)%>'>asp:Label>

                                td>

                                <td>

                                    <asp:Label ID="lblcustomerid" runat="server" Text='<%#eval(customerid)%>'>asp:Label>

                                td>

                                <td>

                                    <asp:Label ID="orderdate" runat="server" Text='<%#eval(orderdate)%>'>asp:Label>

                                td>

                                <td>

                                    <asp:Label ID="shipaddress" runat="server" Text='<%#eval(shipaddress)%>'>asp:Label>

                                td>

                                <td>

                                    <asp:Label ID="shipcountry" runat="server" Text='<%#eval(shipcountry)%>'>asp:Label>

                                td>

                            tr>

                        table>

                    LayoutTemplate>

                asp:ListView>

                <asp:ObjectDataSource ID="orderdatasource" runat="server" SelectMethod="GetOrdersByCustomer"

                    TypeName="BAL.CustomerBAL">

                    <SelectParameters>

                        <asp:ControlParameter ControlID="dpcustomers" Name="customer" PropertyName="SelectedValue"

                            Type="String" />

                    SelectParameters>

                asp:ObjectDataSource>

            ContentTemplate>

        asp:UpdatePanel>