c# - Unable to use more than 1 AsyncfileUpload in master page asp.net -

unable use more 1 asyncfileupload control in masterpage. 1st control works second dead. how solve..

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code is

<asp:asyncfileupload id="asyncfileupload_tech" runat="server" onuploadedcomplete="upload_tech" clientidmode="autoid"/>  <asp:asyncfileupload id="asyncfileupload_comp" runat="server" onuploadedcomplete="upload_comp" clientidmode="autoid"/> 

and cs code is

protected void upload_tech(object sender, eventargs e)     {         string partnoo = session["partno"].tostring();         string filename = system.io.path.getfilename(asyncfileupload_tech.filename);         string filepath = "~/uploads/" + partnoo + "/technical specifications/" + filename;         asyncfileupload_tech.saveas(server.mappath(filepath));     }      protected void upload_comp(object sender, eventargs e)     {         string partnoo = session["partno"].tostring();         string filename = system.io.path.getfilename(asyncfileupload_comp.filename);         string filepath = "~/uploads/" + partnoo + "/complaince/" + filename;         asyncfileupload_comp.saveas(server.mappath(filepath));     } 

please help!!