ajax sliderextender is used where the slider is not shown

i have used ajax sliderextender for the slider provision...im using vs2005.. if i write the below mentioned code then the slider is not shown inthe output page.. where im going wrong.. any help..pls...

    <ajaxToolkit:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server">
    </ajaxToolkit:ToolkitScriptManager>
    <asp:UpdatePanel ID="UpdatePanel1" runat="server">
        <ContentTemplate>
            <asp:TextBox ID="Slider2" runat="server" Text="0" AutoPostBack="true"></asp:TextBox><br />
            <asp:TextBox ID="Slider2_BoundControl" Width="30" runat="server" Visible="true" Text="0"></asp:TextBox><br />
            <ajaxToolkit:SliderExtender ID="SliderExtender2" runat="server" BehaviorID="Slider2"
                TargetControlID="Slider2" BoundControlID="Slider2_BoundControl开发者_如何学编程" Orientation="Horizontal"
                Minimum="-15" Maximum="30" Steps="45" EnableHandleAnimation="true" TooltipText="Select Bar Weight"
                RaiseChangeOnlyOnMouseUp="true">
            </ajaxToolkit:SliderExtender>
        </ContentTemplate>
    </asp:UpdatePanel>

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    ToolkitScriptManager1.RegisterAsyncPostBackControl(Slider2)    
End Sub