Button control inside updatepanel

I have a buttoncontrol inside updatepanel say button1. I have another button, button2 outside the updatePanel.

When i click on the button2, i want to make button1 visible/NotVisible. I have added button2-click as trigger for button1.

<updatePanel ID="UpdatePanel1" UpdateMode="Conditional" runat="Server">
<asputton ID="btnSubmit" runat="server" Text="Submit" />

<Triggers>
<asp:AsyncPostBackTrigger ControlID="btnGo" EventName="click" />
</Triggers>
</updatePanel>

<asp:button ID="btnGo" runat="server"></asp:button>

This is not working. How do i achieve this..anyone has any experiences like this..