ASP.NET Auto refresh gridview updatepanel timer

Hi

I'm new to ajax.

I'm working on visual studio 2005. I install the ajax Min4setup and I add the control toolkit to the controls toolbar.

I created a new website Ajax-Enabled then I add the existing items (all the page) from the old web site to the new one.

I wrote the code below in the page.aspx and the other code in page.aspx.vb but nothing happens, the timer event is not firing.

Code:

 <asp:ScriptManager ID="ScriptManager1" runat="server">
 </asp:ScriptManager>

 <asp:Timer ID="Timer1" runat="server" OnTick="Timer1_Tick" Interval="8000"     Enabled="true">
 </asp:Timer>

 <asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Always" runat="server">  
 <Triggers>  
 <asp:AsyncPostBackTrigger ControlID="Timer1" EventName="Tick" />  
 </Triggers>  
 <ContentTemplate>  
 <asp:Label ID="Label1" runat="server" Text="test" />  
 <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" CellPadding="4"
                                            DataSourceID="SqlDataSource1" ForeColor="#333333" GridLines="None" Width="616px" BorderStyle="Outset">
                                            <RowStyle BackColor="#EFF3FB" />
                                            <Columns>
                                                <asp:BoundField DataField="Sender" HeaderText="Sender"
                                                 SortExpression="MO_NICKNAME_SOURCE_LOG_HIS" />
 <asp:BoundField DataField="DataChat" HeaderText="Conversation" SortExpression="DataChat" />
 <asp:TemplateField HeaderText="Date" SortExpression="DATETIMEIN_LOG_HIS">
 <EditItemTemplate>
 <asp:TextBox ID="TextBox2" runat="server" Text='<%# Bind("DATETIMEIN_LOG_HIS") %>'></asp:TextBox>
 </EditItemTemplate>
 <ItemTemplate>
 <asp:Label ID="Label2" runat="server" Text='<%# Bind("DATETIMEIN_LOG_HIS") %>'></asp:Label>
 </ItemTemplate>
 </asp:TemplateField>
 </Columns>
 <FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
 <PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" />
 <SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" />
 <HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
 <EditRowStyle BackColor="#2461BF" />
 <AlternatingRowStyle BackColor="White" />
 </asp:GridView>
 <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$   ConnectionStrings:OfflineChat_ConnectionString %>"
 SelectCommand="SP_GET_OFFLINE_USER_CHAT" SelectCommandType="StoredProcedure">
 <SelectParameters>
 <asp:SessionParameter Name="MO_OFFLINEUSER" SessionField="ID" Type="String" />
 <asp:QueryStringParameter Name="MO_NICKNAME_REALUSER" QueryStringField="realuserNick"
                                                Type="String" />
 </SelectParameters>
 </asp:SqlDataSource>
 </ContentTemplate>  
 </asp:UpdatePanel> 

 Protected Sub Timer1_Tick(ByVal sender As Object, ByVal e As EventArgs)
{
    Label1.Text = "Grid Refreshed at: "
    '& DateTime.Now.ToString
    GridView1.DataBind()
    UpdatePanel1.Update();
}

Any idea or suggestion will be highly appreciated.

Best Regards,