ajax file upload

i have two ajax file uploaders at the bottom of my aspx page and there upload_complete() handlers in .cs file

my problem is that when i upload file using any of the two uploaders it always call the upload_complete() function of the first one uploader . here is the code

Thanks In Advance.

<asp:ModalPopupExtender ID="mp1" runat="server" PopupControlID="pnluploadaml" TargetControlID="linkuploadamlimage" OkControlID="btnok"
     BackgroundCssClass="modalBackground"></asp:ModalPopupExtender><asp:Panel ID="pnluploadaml" runat="server" CssClass="modalPopup" align="center" style = "display:none" ><asp:AjaxFileUpload runat="server"  ID="UP1" OnUploadComplete="UP1_UploadComplete"  MaximumNumberOfFiles="1" AllowedFileTypes="jpg,jpeg" /></asp:Panel><asp:ModalPopupExtender ID="ModalPopupExtender1" runat="server" PopupControlID="pnluploaddrug" TargetControlID="linkuploaddrugplanimage" OkControlID="btnok" BackgroundCssClass="modalBackground"></asp:ModalPopupExtender><asp:Panel ID="pnluploaddrug" runat="server" CssClass="modalPopup" align="center" style = "display:none" ><asp:AjaxFileUpload ID="UP2" runat="server" OnUploadComplete=UP2_UploadComplete"  MaximumNumberOfFiles="1" AllowedFileTypes="jpg,jpeg" Width="300px"  Height="300px" /></div></asp:Panel>

in .cs it always call upload_complete() handler of fisrt fileuploader