Gridview SelectedIndexChanged event not working in Updatepanel

Hello,

I have a Gridview in an Updatepanel with paging enabled.  When I click on the page link to go to page 2 or 3 the entire site still refreshes.  Also, I have SelectedIndexChanged event enable to kick of the populating of a listbox.  That does not seem to be updating in the Updatepanle either.  I read about triggers but not sure how to use them on the listbox.  Any ideas?

Many thanks,

James

GRIDEVIEW

<asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Conditional" runat="server">
                    <ContentTemplate>
                        <asp:GridView ID="GridViewProgram" runat="server" AllowPaging="True"
                            AllowSorting="True" AutoGenerateColumns="False" DataSourceID="dsProgram"
                            onselectedindexchanged="GridViewProgram_SelectedIndexChanged"
                            Width="1000px" PageSize="8">
                            <Columns>
                                <asp:CommandField ButtonType="Button" ShowSelectButton="True" />
                                <asp:BoundField DataField="ID" HeaderText="ID" SortExpression="ID" />
                                <asp:BoundField DataField="EVENT DATE" HeaderText="EVENT DATE" ReadOnly="True"
                                    SortExpression="EVENT DATE" />
                                <asp:BoundField DataField="PROGRAM NAME" HeaderText="PROGRAM NAME"
                                    SortExpression="PROGRAM NAME" />
                                <asp:BoundField DataField="TYPE" HeaderText="TYPE" SortExpression="TYPE" />
                                <asp:BoundField DataField="SUB TYPE" HeaderText="SUB TYPE"
                                    SortExpression="SUB TYPE" />
                                <asp:BoundField DataField="STATUS" HeaderText="STATUS"
                                    SortExpression="STATUS" />
                                <asp:BoundField DataField="PROGRAM CITY" HeaderText="PROGRAM CITY"
                                    SortExpression="PROGRAM CITY" />
                                <asp:BoundField DataField="PROGRAM STATE" HeaderText="PROGRAM STATE"
                                    SortExpression="PROGRAM STATE" />
                                <asp:BoundField DataField="PROGRAM COUNTRY" HeaderText="PROGRAM COUNTRY"
                                    SortExpression="PROGRAM COUNTRY" />
                                <asp:BoundField DataField="OFFICE" HeaderText="OFFICE"
                                    SortExpression="OFFICE" />
                            </Columns>
                            <SelectedRowStyle BackColor="#C86A02" Font-Bold="True" ForeColor="White" />
                        </asp:GridView>
                    </ContentTemplate>       
                 </asp:UpdatePanel>

LISTBOX

<asp:ListBox ID="lbOffice" runat="server" AutoPostBack="True"
                    DataSourceID="dsOffice" DataTextField="OFFICE" DataValueField="OFFICE"
                    Height="115px" onselectedindexchanged="lbOffice_SelectedIndexChanged"
                    SelectionMode="Multiple" Width="100%" Font-Names="Arial" Font-Size="8pt"></asp:ListBox>