<asp:Button ID="btnInserisci" runat="server" Height="28px" Text="Inserisci" Width="80px"/>
                                <cc1:ConfirmButtonExtender ID="CBE1" runat="server" 
                                    ConfirmText="Vuoi stampare il RAV?" TargetControlID="btnInserisci">
                                </cc1:ConfirmButtonExtender>