Ajax slideshowextender is not working!

Hi,

Please, can anyone help me out or give me any idea why my ajax slideshowextender is not working.

Here is my code. Thanks in advanced.

<script runat="Server" type="text/C#">
    [System.Web.Services.WebMethod]
    [System.Web.Script.Services.ScriptMethod]
    public static AjaxControlToolkit.Slide[] GetSlides()
    {
        AjaxControlToolkit.Slide[] slides = new AjaxControlToolkit.Slide[5];

        slides[0] = new AjaxControlToolkit.Slide("images/Wallpaper 01.jpg", "Ascent", "Cool moon night...");
        slides[1] = new AjaxControlToolkit.Slide("images/Wallpaper 02.jpg", "Desert", "Red moon desert...");
        slides[2] = new AjaxControlToolkit.Slide("images/Wallpaper 03.jpg", "Tulips", "Beautiful tulips...");
        slides[3] = new AjaxControlToolkit.Slide("images/Wallpaper 04.jpg", "Autumn", "Way to home...");
        slides[4] = new AjaxControlToolkit.Slide("images/Wallpaper 05.jpg", "Stonehenge", "Age of mythology...");
        return (slides);
    }  
  </script>
<div class="center1 marginauto">
    <ajax:ScriptManager ID="scriptmanager" runat="server"></ajax:ScriptManager>    
    <div style="text-align:center">
        <asp:Label runat="Server" ID="lblTitle" /><br />
            <asp:Image ID="ctlImage" runat="server" ImageUrl="~/Images/Wallpaper 01.jpg" AlternateText="microsoft" width="380"  height="179" />
            <asp:Label runat="server" ID="lblDesc" ></asp:Label><br />
        <ajax:SlideShowExtender ID="SlideShowExtender1" runat="server"
            TargetControlID="ctlImage"
            SlideShowServiceMethod="RetrieveSlides"
            Loop="true" AutoPlay="true" ImageTitleLabelID="lblTitle" ImageDescriptionLabelID="lblDesc"></ajax:SlideShowExtender>                    
    </div>
</div>