Confirmation and task after the updation of update panel

Question

 Hi all,
Recently I came across a task in which I used a update panel and a update progress. Everything is working fine except the last task when the update panel is updated is not taking place. For eg: I am downloading some data. For that I am making user to see the update panel with the progress indicator image. When the data is collected and written in the desired format and it has to come in a dialogue box over the screen, nothing happens. Neither I am able to show user a confirmation message after the finishing the update process. Am i missing something ??? And one more thing during the panel is updated I freeze the GUI using a div and opacity of the div. Is it because of that ? Here is my HTML mark up:-

<asp:UpdatePanel ID="UpdatePanel1" runat="server">                     <ContentTemplate>                                 <asp:Button ID="btnDwnload" runat="server" OnClick="btnDwnload_Click" Style="text-align: center"                                     Text="Download" UseSubmitBehavior="false" />                                     </ContentTemplate>                 </asp:UpdatePanel>                             </td>                             <td style="text-align: center">                             <asp:UpdateProgress ID="UpdateProgress2" runat="server" AssociatedUpdatePanelID="UpdatePanel2">                             <ProgressTemplate>                             <div style="top: 0px; height: 1000px; background-color: White; opacity: 0.75; filter: alpha(opacity=55);                         vertical-align: middle; left: 0px; z-index: 999999; width: 1500px; position: absolute;                         text-align: center;">                                                  </div>                                 <asp:Image ID="Image2" runat="server" ImageUrl="~/images/indicator.gif" Width="100px" />                                 <br />                                 Processing...                             </ProgressTemplate>                         </asp:UpdateProgress>