I try to return a value, after calling the method "UploadData."
I try to Save to "listaid"
But I can not do.

(Sorry for my bad English)

<script type="text/javascript">
 var successHandler = function (form, action) {


<ext:Button ID="SaveButton" runat="server" Text="Subir Datos" Disabled="true"  AnchorHorizontal="100%" Scale="Small" IconAlign="Bottom" Icon="PageWhiteExcel"   >
                        <Click Url="/Data/UploadData/" IsUpload="true" CleanRequest="true" Method="POST"   
                                title   : 'Error', 
                                msg     : 'Archivo no compatible. Error al procesarlo', 
                                minWidth: 200, 
                                modal   : true, 
                                icon    : Ext.Msg.ERROR, 
                                buttons : Ext.Msg.OK 

                                    <ext:Parameter Name="id" Value="#{camp}.getValue()" Mode="Raw" />                          

                <ext:Hidden ID="listaid" Text="" runat="server"></ext:Hidden>

 public AjaxFormResult UploadData(string id, FormCollection values)
response.ExtraParams.Add(new Parameter { Name = "mailingid", Value = mailingid, Mode = ParameterMode.Value });
response.Success = true;
response.IsUpload = true;
return response;
Any ideas? Thank you very much