Get Value of Fileuploader from model popup

See more:

ASP.NET

C#3.5

File-Upload

I have a aspx page with model popup extender.And that contains FileUploader.I want Progrss bar while Uploading but i am not getting value of fileuploader.It is giving 0.Their are no separate child and parent page.I have used model popup extender on parent page only..

<asp:ModalPopupExtender ID="mpnlPopup" runat="server" TargetControlID="btnModalTarget"
                PopupControlID="Panel2" BackgroundCssClass="modalBackground" DropShadow="false"
                OnOkScript="onOk()" DynamicServicePath="" Enabled="True" RepositionMode="RepositionOnWindowResize"
                CancelControlID="btnCloseImage">
            </asp:ModalPopupExtender>

Now This Popup Control Id contains panel

<asp:FileUpload ID="UploadImage" runat="server" Width="200px" CssClass="appfileupload" />                                            
                                                                                                     <asp:Button ID="btnUpload" runat="server" Text="Save" CausesValidation="true" ValidationGroup="CheckImage" OnClick="btnUpload_OnClick" OnClientClick="return ProgressBar()" />  
  <asp:Button ID="btnCloseImage" runat="server" Text="Close" />

Now OnClientClick="return ProgressBar()" goes to the function.bUT UploadImage.ClientID VALUE is 0.hOW TO GET THIS VALUE AND MAKE MY PROGRESS BAR IN WORKING CONDITION

<script language="javascript" type="text/javascript">
        var size = 2;
        var id = 0;

        function ProgressBar() {
            alert("in");

            var ID = $("<%#UploadImage.ClientID %>").parent.valueOf();
           alert(id);
           if (document.getElementById('<%#UploadImage.ClientID %>').value != "") {

               alert("va");
                document.getElementById("divProgress").style.display = "block";
                document.getElementById("divUpload").style.display = "block";
                id = setInterval("progress()", 20);
                return true;
           }
            else {
                alert("Select a file to upload");
                return false;
           }

        }

        function progress() {
            size = size + 1;
            if (size > 299) {
                clearTimeout(id);
            }
            document.getElementById("divProgress").style.width = size + "pt";
            document.getElementById("<%#lblPercentage.ClientID %>").firstChild.data = parseInt(size / 3) + "%";
        }

    </script>

[Edit member="Tadit"]
Added pre tags.
[/Edit]