My trigger doesn't work in updatepanel?

Question

i need to refresh UpdatePanel3'content , but if i click first btnTranslate , it doesn't work, but second click it works?

 <asp:Button ID="btnTranslate" runat="server" OnClick="btnTranslate_Click" Text=">>"
                        class="buttons" ValidationGroup="ValidForm" />
                </td>
                <td>
                    <asp:UpdatePanel ID="UpdatePanel3" runat="server">
                        <ContentTemplate>
                            <asp:TextBox ID="txtResults" classs="txtBoxesMultyLine" runat="server" Height="266px"
                                TextMode="MultiLine" Width="363px"></asp:TextBox>
                        </ContentTemplate>
                        <Triggers>
                            <asp:AsyncPostBackTrigger ControlID="drpDatabases" EventName="SelectedIndexChanged" />
                            <asp:AsyncPostBackTrigger ControlID="drpProcess" EventName="SelectedIndexChanged" />
                            <asp:AsyncPostBackTrigger ControlID="btnTranslate" EventName="Click" />
                        </Triggers>
                    </asp:UpdatePanel>

Answer 1

Do you have any idea?