DevExpress Popup Control in asp.net

<dx:ASPxPopupControl ID="ASPxPopupControl1" Width="350" Height="300" PopupHorizontalAlign="WindowCenter"         PopupVerticalAlign="WindowCenter" runat="server" HeaderText="Select Files"           CloseAction="CloseButton" ClientInstanceName="ASPxPopCtrlfileUpload">         <ContentCollection>               <dx:PopupControlContentControl ID="popupforUpload" Visible="true" runat="server">                              <table width="95%">                 <tr>                                      <td>                      <asp:Label ID="lblFiletype" runat="server" Visible="false"></asp:Label>                   </td>                 </tr>                 <tr>                   <td>                     Select Type:                   </td>                    <td>                      <asp:RadioButtonList ID="rblLink" runat="server" AutoPostBack="true" RepeatLayout="Flow"                       RepeatDirection="Horizontal" OnSelectedIndexChanged="rblLink_SelectedIndexChanged">                       <asp:ListItem Text="File" Value="1" Selected="True"></asp:ListItem>                    <asp:ListItem Text="Link" Value="0"></asp:ListItem>                                     </asp:RadioButtonList>                   </td>                 </tr>                  <tr id="trfile" runat="server" visible="true">                   <td>                     File :                   </td>                    <td>                      <asp:FileUpload ID="fUpload" runat="server" />                   </td>                 </tr>                  <tr id="trlink" runat="server" visible="false">                   <td>                     Link :                   </td>                    <td>                      <asp:TextBox ID="txtlink" runat="server" />                   </td>                 </tr>                   <tr>                                      <td colspan="2" align="center">                                         </td>                 </tr>                  <tr>                                      <td colspan="2" align="center">                      <asp:Button ID="btnSaveFile" runat="server"  Text="Save File" onclick="btnSaveFile_Click" />                   </td>                 </tr>               </table>                                   <asp:UpdatePanel ID="upnlFile" runat="server"><ContentTemplate>                          </ContentTemplate>       </asp:UpdatePanel>             </dx:PopupControlContentControl>                     </ContentCollection>     </dx:ASPxPopupControl>