I am exporting the grid data to the PDF file by using iTextSharp. I am searching the billno and fetched data is relating on the grid and control( in ext.net). Searching can be in 3 ways: 1. By inserting billno and pressing enter in combo box 2. By inserting billno and click the trigger in combo 3. By Selecting billno from combo Now after that I click on ToPDF button to export data. If I perform 2 & 3, its working fine, but when I perform 1 then a window comes with header Request failure, Status text - communication failure. As the Grid data are exported also, but y this window appears that I m nt getting.
My Code is as below .cs

protected void ToPDF(object sender, EventArgs e)
{
      //Code
}
.aspx
<ext:ComponentMenuItem ID="ComponentMenuItem1" runat="server">
                                                        <Component>
                                                               <ext:ComboBox ID="cmbSearchBillno" runat="server" 
                                                                    EmptyText="Select Bill No" 
                                                                    ForceSelection="true"   
                                                                    StoreID="BillMasterStore"  
                                                                    DisplayField="Billno" ValueField="BillId">
                                                                    <Triggers>
                                                                        <ext:FieldTrigger Icon="Search" />
                                                                    </Triggers>
                                                                     <Listeners>
                                                                        <SpecialKey Fn="enterKeyPressHandler" />
                                                                    </Listeners>
                                                                    <DirectEvents>
                                                                         <%--<SpecialKey OnEvent="enterKeyPressHandler" ShowWarningOnFailure="false" Timeout="60000" StopEvent="true">
                                                                            <ExtraParams>
                                                                                <ext:Parameter Name="key" Value="e.getKey()" Mode="Raw">
                                                                                </ext:Parameter>
                                                                                <ext:Parameter Name="BillNo" Value="this.getText()"  Mode="Raw"></ext:Parameter>
                                                                            </ExtraParams>
                                                                        </SpecialKey>--%>
                                                                        <Select OnEvent="ChangeBillno">
                                                                            <ExtraParams>
                                                                                <ext:Parameter Name="BillNo" Value="record.id" Mode="Raw"></ext:Parameter>
                                                                            </ExtraParams>
                                                                        </Select>
                                                                        <TriggerClick OnEvent="SearchBillDetails" >
                                                                            <ExtraParams>
                                                                                <ext:Parameter Name="BillNo" Value="this.getText()" Mode="Raw"></ext:Parameter>
                                                                            </ExtraParams>
                                                                        </TriggerClick>
                                                                    </DirectEvents> 

                                                                </ext:ComboBox>
                                                        </Component>                        
                                                    </ext:ComponentMenuItem>

 <ext:Button ID="btnPdf" runat="server" Text="To PDF" AutoPostBack="true" OnClick="ToPDF"  Icon="PageWhiteAcrobat">
                                        <Listeners>
                                            <Click Fn="saveData" />
                                        </Listeners>
                                     </ext:Button>

<script type="text/javascript">

       var enterKeyPressHandler = function (f, e) {
           if (e.getKey() == e.ENTER) 
           {
                var billno=this.getText();
                Ext.net.DirectMethods.SearchBillno(billno);

                e.stopEvent();
                this.send();
           }
       }


         var saveData = function () {
           GridData.setValue(Ext.encode(GridService.getRowsValues({selectedOnly : false,excludeId:true})));
        };


    </script>