Custom RadTabStrip styles not working in DNN Desktop Modules

[Ravi]

Hi Expert,

I am using the Custom RadTabStrip  in DNN Custom Modules. I am unable to view the UI that I am looking for . Some styles problem occurring in that. But the same code is working fine in the Ordinary .ascx files in the same DNN Project.
<%@ Control Language="C#" AutoEventWireup="true" CodeFile="View.ascx.cs" Inherits="DotNetNuke.Modules.CourseSearch.View" %>
<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %>
 <%@ Register Assembly="Telerik.Web.UI" Namespace="Telerik.Web.UI" TagPrefix="telerik" %>
  <style type="text/css">
        .HovCSS
        {
            background: url('DesktopModules/CourseSearch/images/tab1.gif') no-repeat;
            width: 139px;
            height: 24px;
        }
        .OutCSS
        {
            background: url('DesktopModules/CourseSearch/images/tab2.gif') no-repeat;
            width: 139px;
            height: 24px;
        }
        .SelCss
        {
            background: url('DesktopModules/CourseSearch/images/tab1.gif') no-repeat;
            width: 139px;
            height: 24px;
        }
    </style>
 <telerik:RadTabStrip ID="RadTabStrip1" runat="server" MultiPageID="rmp"
            EnableEmbeddedSkins="false">
            <Tabs>
                <telerik:RadTab Value="Tab1" Text="MyTab1" Selected="true" HoveredCssClass="HovCSS" OuterCssClass="OutCSS"
                    SelectedCssClass="SelCSS">
                </telerik:RadTab>
                <telerik:RadTab Value="Tab2" Text="MyTab2" HoveredCssClass="HovCSS" OuterCssClass="OutCSS" SelectedCssClass="SelCSS">
                </telerik:RadTab>
                <telerik:RadTab Value="Tab3" Text="MyTab3" HoveredCssClass="HovCSS" OuterCssClass="OutCSS" SelectedCssClass="SelCSS">
                </telerik:RadTab>
            </Tabs>
        </telerik:RadTabStrip>
        <telerik:RadMultiPage ID="rmp" SelectedIndex="0" runat="server" Width="100%">
            <telerik:RadPageView ID="FirstPage" runat="server">
                First Page
            </telerik:RadPageView>
            <telerik:RadPageView ID="RadPageView1" runat="server">
                Second Page
            </telerik:RadPageView>
            <telerik:RadPageView ID="RadPageView2" runat="server">
                Third Page
            </telerik:RadPageView>
        </telerik:RadMultiPage>

Please guide me!!!!!!!! to resolve this issue. Its urgent.....

Thanks in Advance!
RaviChandran